$.$ If you have the following MIPS program, if forwarding is not used, then:

add $sO$,$ $tO$,$ $t$1$

sub $t$2,$ $sO$,$ $t$3$

a$.$ The speed up $=(2$x$5)/9$

b$.$ The speed up $-(2$x$5)/(5+1)$

c$.$ None of the above