Question

in which case does secondary succession not occur? after a forest fire in an area with only bare rock after a drought

Explanation:

Secondary succession occurs in areas where a disturbance has destroyed an existing ecosystem but left the soil intact. A forest fire and a drought can both lead to secondary succession as the soil remains. However, an area with only bare rock has no soil initially, and primary succession (which starts with pioneer species colonizing bare rock to create soil over time) would occur here, not secondary succession.

Answer:

in an area with only bare rock