LDAC $9,$ LDAC @$9,$ LDAC R$,$ LDAC @ R$,$ LDAC #$9,$ LDAC $$9,$ LDAC $9($X$)$

Before fetching each instruction, $PC$ contains $7,R$ contains $9,$ and $x$ contains $0.($All values in this

problem are specified in decimal notation.$)$ Memory locations $0$ to $19$ contain the values $10$ to $29,$

respectively. List all addressing modes that store the following values in AC$.$ All values are given in

decimal notation.

$($a$)$ Instruction sets $AC=9$

$($b$)$ Instruction sets $AC=19$

$($c$)$ Instruction sets $AC=29$