The designers of the MIPS architecture only include one memory addressing mode $($Displacement Mode$)$ when setting up the ISA. $($Remember that an address mode is a way to specify the effective address for load$/$store instructions.$)$

Below, provide the answer to the following two questions:

A$)$ With regard to the CPU execution time formula, explain one benefit that would be gained by adding another address mode.

B$)$ With regard to the CPU execution time formula, explain one cost that would have to be paid for the addition of another address mode.