Final answer:
Cooling is not a process involved in the formation of sedimentary rock; instead, compaction and cementation are key to forming such rocks.
Step-by-step explanation:
The process not involved in the formation of sedimentary rock is A) Cooling. The formation of sedimentary rocks primarily involves the processes of compaction and cementation. Weathering and erosion are responsible for breaking down pre-existing rocks into smaller particles, which are then transported and deposited elsewhere. The deposited sediments are later compacted as more layers build up on top of them, and cemented when minerals precipitate out of water, filling the spaces between the sediments and binding them together.