Select the most appropriate option that can substitute the highlighted segment in the following sentence. If there is no need to substitute it, select ‘No substitution required’.
The invigilator did not know that the four friends were exchanging notes right at the front of him.

Correct option is D

The correct phrase is “in front of him.”
Explanation:
· The correct prepositional phrase indicating position is “in front of.”
· “At the front of” is used for locations, buildings etc., not for people.
Grammatical Rule Used:
Use ‘in front of’ when describing position relative to a person or object.
Example: The car stopped in front of the gate.
Meanings of other options:
· of front of him – ❌ grammatically incorrect
· for front of him – ❌ incorrect usage
· No substitution required – ❌ incorrect as original phrase is wrong