I last saw her . . . . . . . . the car park.

The correct preposition is at because it is used to indicate a specific place or location where an action happens. The sentence means that the last time the speaker saw her was at the car park.

We use at with particular places such as at the bus stop, at the station, at the airport, at the entrance, and at the car park when referring to a specific location rather than being inside or on something.

The other options are incorrect:

• in is used when someone is inside an enclosed space (e.g., in the room, in the car). While "in the car park" can sometimes be used to emphasize being inside the parking area, the standard answer for identifying the location where someone was seen is at the car park.

• of is not used to indicate location in this context.

• on is used for surfaces or certain forms of transport (e.g., on the table, on the bus) and is not appropriate with car park.

Exam Tip: Use at for a specific point or place, in for an enclosed area, and on for a surface. Questions testing the difference between at and in are common in competitive English exams.