Grammar Error Identification

The question asks to identify the INCORRECT part in the sentence: "I requested that he should be given the driving test today instead of tomorrow."

Analyzing Sentence Components

Let's examine each part mentioned in the options:

• $requested that$: This structure is grammatically correct for introducing a subordinate clause expressing a request or demand.
• $should be given$: This part contains the error. When using verbs like 'request', 'suggest', 'demand', etc., followed by 'that', the subjunctive mood is preferred. The subjunctive form omits the modal verb 'should'. The correct form is 'be given'.
• $the driving test$: This noun phrase is appropriate and grammatically correct in this context.
• $instead of tomorrow$: This prepositional phrase correctly provides an alternative time, contrasting 'today' with 'tomorrow'.

Correct Usage Explanation

Verbs expressing commands, suggestions, or requests (like 'request') often trigger the subjunctive mood in the following clause introduced by 'that'. The subjunctive mood uses the base form of the verb.

• Incorrect: I requested that he should be given...
• Correct: I requested that he be given...

Alternatively, the sentence could be rephrased, but the structure "requested that he should be given" is considered incorrect or unnecessarily wordy in standard English.

Conclusion

The erroneous part of the sentence is Option B: $should be given$.