How is memory accessed in RISC architecture?

The correct answer is A. Load and store instruction.

A load instruction fetches data from memory into a register, while a store instruction stores data from a register to memory. These instructions are used to access memory in RISC architecture.

B. Opcode instruction is the instruction that tells the processor what operation to perform. C. Memory instruction is not a valid instruction in RISC architecture. D. Bus instruction is used to control the flow of data between the processor and memory.