$8.$ Aiken is running the following MIPS program. What are the possible number of instructions executed in total assuming that the program does not result in an error, if you can start with any starting value of $\backslash$$s$1$ and $\backslash$$s$2$ and with any possible memory content?

$```$

addi $t$0,$ $s$1,0$

addi $t$1,$ $zero, $1$

addi $t$2,$ $s$2,0$

loop: lb $t$3,0($$s$2)$

andi $t$4,$ $t$3,0$x$1$

beq $t$4,$ $zero, else

sll $t$1,$ $t$1,1$

else: addi $t$0,$ $t$0,1$

addi $s$2,$ $s$2,1$

bne $t$3,$ $zero, loop

$```$

A$.9$

B$.14$

C$.15$

D$.43$

E$.63$