three instruction opcodes. For this question,

we add two more for a total of five. They full set of opcodes, in binary, is as follows:

$0001=$ Load AC from memory $0011=$ Load AC from I$/$O device

$0010=$ Store AC to memory $0111=$ Store AC to I$/$O device

$0101=$ Add to AC from memory

For the new opcodes $0011$ and $0111,$ the address field in the inst