Correct Option: A
$\uparrow$ has higer precedence than $\{*,+,-,/ \}$
So, if op $ = \uparrow$ implies, we need to evaluate the right hand side of $\uparrow$ first and then do the lhs part, which would definitely require us to store the value of lhs
but if its a '$+$' or '$*$' , we don't need to store the values evaluated, and on the go can do the operation directly on one register.