In a $\Delta$le ABC let $\angle C=\large\frac{\pi}{2}$ if $r$ is the radius and R is the circumference of the $\Delta$le ABC then $2(r+R)$ equals

Question

$(a)\;c+a\qquad(b)\;a+b+c\qquad(c)\;a+b\qquad(d)\;b+c$