The question requires us to fill in two blanks in a sentence to make it grammatically correct and logically sound. The sentence is: "If you choose plan P, you will have to ________ plan Q, as these two are mutually ________". This implies a relationship between two plans, P and Q, where selecting one means the other cannot be selected.

Plan Relationship Analysis

Let's break down the sentence to understand the relationship between plan P and plan Q.

• The phrase "If you choose plan P, you will have to..." suggests that choosing plan P necessitates a particular action regarding plan Q. This action should indicate that plan Q is no longer an option.
• The reason for this necessity is given by "as these two are mutually ________". The word "mutually" indicates a reciprocal relationship between the two plans.

Analyzing the First Blank: The Action Towards Plan Q

If choosing plan P means you cannot choose plan Q, the word for the first blank should convey the idea of giving up, abandoning, or not choosing plan Q.

• Forgo: To forgo means to abstain from, give up, or do without. If you choose plan P, you have to forgo plan Q, meaning you give up the option of choosing plan Q. This fits perfectly.
• Forget: To forget means to fail to recall or remember. This doesn't fit the context of making a choice between plans.
• Accept: To accept means to agree to receive or undertake. If you choose plan P, you would not accept plan Q; rather, you would not choose it.
• Adopt: To adopt means to take up or begin to use or follow. This is similar to 'choose' or 'accept' and doesn't fit the negative implication for plan Q.

Based on this, "forgo" is the most suitable word for the first blank.

Analyzing the Second Blank: The Mutual Relationship

The second blank describes the nature of the relationship between plan P and plan Q. Since choosing one means the other cannot be chosen, they must have a relationship where their existence or selection is incompatible.

• Exclusive: The term "mutually exclusive" means that two or more events or conditions cannot occur at the same time. If plan P is chosen, plan Q cannot be chosen, and vice-versa. This aligns perfectly with the sentence's meaning.
• Inclusive: "Mutually inclusive" would imply that if one plan is chosen, the other must also be chosen, or they are part of a larger whole that always exists together. This contradicts the idea of having to give up one if the other is chosen.
• Exhaustive: "Mutually exhaustive" means that between the given options, all possibilities are covered. For example, a coin flip is either heads or tails, making those two outcomes mutually exhaustive (and also mutually exclusive). While it can describe a set of options, it doesn't directly imply that choosing one means giving up the other in the way "exclusive" does. Here, the focus is on the inability to choose both.
• Intrusive: "Intrusive" means causing disruption or annoyance through being unwelcome or uninvited. "Mutually intrusive" does not describe a logical relationship between choices.

Therefore, "exclusive" is the most appropriate word for the second blank, forming the common phrase "mutually exclusive".

Combining the Best Options

Let's insert the most suitable words into the sentence:

"If you choose plan P, you will have to forgo plan Q, as these two are mutually exclusive."

This sentence now makes complete sense: choosing one plan means you must give up the other because they cannot both be selected simultaneously.

Final Check of Options

Based on the detailed analysis, option 1 "forgo, exclusive" is the only pair that logically completes the sentence, accurately reflecting the relationship between plan P and plan Q.