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Solution

Control memory is used in microprogrammed control unit, not in hardwired control unit. So, option (a) is false.

Program control instructions change the normal sequential execution of a program.

Examples are branch, jump, call and return instructions.

So, option (b) is true.

Register indirect addressing uses a register containing memory address, while displacement addressing uses base plus offset. So, option (c) is false.

Interrupts affect CPU utilization because CPU can handle I/O and events efficiently. So, option (d) is false.