Which of the following is an appropriate CPU operation associated with cache memory?

Which of the following is an appropriate CPU operation associated with cache memory?

1. a) When a cache hit occurs, the CPU fetches data from ROM.
2. b) When a cache hit occurs, the CPU fetches data from main memory.
3. c) When a cache miss occurs, the CPU fetches data from cache memory.
4. d) When a cache miss occurs, the CPU fetches data from main memory.