$(9)$ When the following VHDL code runs with v $="10110110",$ the final value of n is $7.$ What is the statement at XXX$?$ n :$=0$; for k in $0$ to $7$ loop if v$($k$)=1$ then XXX; else n :$=$ n$-1$; end if; end loop; a$.$ n :$=$ n $+1$; b$.$ n :$=$ n $+2$; c$.$ n :$=$ n$-1$; d$.$ n :$=$ n$-2$;