Q. Listen! I think there is someone . . . . . . . . the front door.
✅ Correct Answer: (A)
at
Explanation: 'At' indicates specific time, location or position. Hence it is the correct preposition to be used in the sentence.
Explanation by: Team MCQ Buddy
'At' indicates specific time, location or position. Hence it is the correct preposition to be used in the sentence.