In which of the following sentences is the preposition used correctly?

✂️ a) She is responsible at organizing the annual conference.

✂️ b) They are arriving at the airport in the afternoon.

✂️ c) He insisted with going to the meeting despite being sick.

✂️ d) I will meet you under the bus stop near your house.

✂️ e) We discussed about the project to hours before making a decision.

Responda: In which of the following sentences is the preposition used correctly?