We have to find $q-p$
$q$ is nothing but address of $B\left [ 5 \right ]$, say it is $1010$
and $B\left [ 4 \right ]$ is $1008.$
Then $q-p=\frac{1010-1008}{size of(int)}=1$
Now, we have to find $((int)$&$(p\rightarrow c))-((int)p)$.
Here $c$ is $char$ and typecasted to $int.$
And, $((int)p)$ is 'short int' type , it's size '4B'
So, $((int)$&$(p\rightarrow c))-((int)p)=2$
Answer will be $(3)$