A hypothetical microprocessor operates only on the registers in the CPU. It can perform three address instructions. If its instruction length is $2$ byte $(16$ bits$)$ as pert the format Operation, Destination Register, Source Register, source Register

a$.$ What is the maximum number of operations it can have with minimum number of registers? $[1\mathrm{.}5$ Marks$]$

b$.$ What is the minimum number of operations it can have with maximum number of registers? $[1\mathrm{.}5$ Marks$]$