Given the following recursive function which of the following is TRUE about this function?

defgcd$1(m,n)$:

$r=m\%n$

if $r==0$ :

return $n$;

else:

return $gcd1(n,r)$

a$.r$ is a value that is shared between all the recursive calls

b$.$ This function recursively calls itself until the remainder is zero

c$.$ The recursive case of this function always sent the smaller input value to the next call

d$.$ This function has no base case