The instruction that is used as prefix to an instruction to execute it repeatedly until the CX register becomes zero is
A. SCAS
B. REP
C. CMPS
D. STOS
Answer:A
The instruction that is used as prefix to an instruction to execute it repeatedly until the CX register becomes zero is
A. SCAS B. REP C. CMPS D. STOS
Explanation: The instruction to which the REP is prefix, is executed repeatedly until CX register becomes zero. When CX becomes zero, the execution proceeds to the next instruction in sequence.