Preposition with Obstacle

The question asks us to choose the correct preposition to complete the sentence: "Illiteracy is an obstacle ______ progress." We need to understand how the word 'obstacle' is typically used with prepositions in English grammar.

'Obstacle' means something that blocks your way or prevents you from doing something. When we talk about something being an obstacle to achieving a goal or making progress, we usually use the preposition 'to'.

Analyzing the Preposition Options

Let's look at the given options and see which one fits best with 'obstacle' in this context:

• for: While 'for' can indicate purpose or recipient, 'obstacle for progress' isn't the standard idiomatic phrase. You might say 'an obstacle for someone' (meaning it's an obstacle that affects them), but when indicating what is being hindered, 'to' is used.
• in: 'In' usually indicates location or state. 'Obstacle in progress' doesn't correctly convey that illiteracy hinders the process of progress itself.
• with: 'With' often indicates accompaniment or connection. 'Obstacle with progress' doesn't make sense in this context; it doesn't show that illiteracy is hindering progress.
• to: The phrase 'obstacle to' is the standard way to express that something is blocking or hindering something else, especially a goal, achievement, or process like progress. Illiteracy is something that blocks or makes progress difficult.

Correct Usage Examples

Here are some examples showing the correct usage of 'obstacle to':

• Lack of funding is an obstacle to completing the project.
• Fear of failure can be a major obstacle to personal growth.
• Poor infrastructure is an obstacle to economic development.

In the given sentence, illiteracy is what hinders or blocks progress. Therefore, the correct preposition is 'to'.

The complete sentence is:

Illiteracy is an obstacle to progress.

Based on standard English grammar and common usage, 'obstacle to' is the correct phrase.