a) Fetch, Decode, Write
b) Fetch, Decode, Execute
c) Fetch, Execute, Write
d) Fetch, Decode, Execute, Write

Answer: b
Explanation: ARM7 core has 3-stage pipeline that increases instruction flow through processor up to three times. So each instruction is executed in 3 stages:
Fetch – instruction is fetched from memory and placed in pipeline
Decode – instruction is fetched and data-path signals prepared for next cycle
Execute – instruction from prepared data-path reads from registry bank, shifts operand to ALU and writes generated result to dominant register.