Assume you have the following code:

int module$($int $n)$

$\{$

if $)==(1$

return $1$;

else

return $(n+$module$(n-1))$ :

The above code ends up with which recurrence?

a$.T(n)=T(n-1)+n$

b$.T(n)=T(n-1)+cn-1$

c$.T(n)=T(n-1)+c$

d$.T(n)=T(\frac{n}{2})+1$