In each of the following questions, find out which part of the sentence has an error. The sentence is divided into three parts labelled A, B and C, and part D indicates that the sentence has no error. Identify the part that contains a grammatical or idiomatic error in the sentence: I told him on his face that he could not hope to pass the stringent Medical examination of the Service Selection Board.

Introduction / Context:
This error spotting question checks your knowledge of English idioms and natural expressions. The sentence describes speaking very frankly to someone about his chances of passing a strict medical examination. You must decide which part of the sentence sounds incorrect or unnatural in standard English usage. Sometimes, the error is not in basic grammar but in the use of a preposition within a fixed phrase.

Given Data / Assumptions:
- Full sentence: I told him on his face that he could not hope to pass the stringent Medical examination of the Service Selection Board. - Part A: I told him on his face. - Part B: that he could not hope. - Part C: to pass the stringent Medical examination of the Service Selection Board. - Part D: The sentence is grammatically correct; no error.

Concept / Approach:
The idiomatic expression in English is to say something to someone's face, meaning to say it very directly, without hiding it behind their back. The phrase on his face is not the accepted form in this context. The rest of the sentence, including the clause about not being able to hope to pass a stringent medical examination, is grammatically acceptable. Therefore, your focus should be on locating the incorrect preposition in the fixed phrase and marking that part as the error.

Step-by-Step Solution:
Step 1: Examine part A, I told him on his face. This is meant to express directness, but the correct idiom is I told him to his face. Step 2: Examine part B, that he could not hope. This structure is correct, as could not hope introduces what he realistically cannot expect. Step 3: Examine part C, to pass the stringent Medical examination of the Service Selection Board. This part is grammatically sound and describes a demanding test. Step 4: Since only part A misuses the preposition on instead of to, part A contains the error.

Verification / Alternative check:
Rewrite the sentence with the correct idiom: I told him to his face that he could not hope to pass the stringent Medical examination of the Service Selection Board. This revised sentence reads naturally and is consistent with standard English usage. No further changes are necessary. This confirms that the only real problem in the original sentence is the incorrect phrase on his face, and therefore part A must be selected as the error bearing segment.

Why Other Options Are Wrong:
Part B is correct because the use of could not hope is suitable when expressing that success is very unlikely. Part C is correct because the phrase to pass the stringent Medical examination of the Service Selection Board is grammatically well formed. Part D is wrong because the sentence as given does have an idiomatic error in part A.

Common Pitfalls:
Learners who translate directly from their mother tongue often produce literal expressions like on his face instead of to his face. Such small preposition mistakes can change an otherwise good sentence into an incorrect one in an exam. To avoid this, pay attention to fixed expressions while reading or listening to English. Phrases like to his face, behind his back, and face up to a problem are standard and need to be memorised as units. Regular exposure to authentic language helps you internalise these forms and recognise errors quickly.

Final Answer:
The part containing the error is I told him on his face, which should be corrected to I told him to his face.