Evaluate $40^{\large\circ}30'$

Question

$(a)\;\big(\large\frac{41}{2}\big)^{\large\circ}$$\qquad(b)\;81^{\large\circ}\qquad(c)\;\big(\large\frac{81}{2}\big)^{\large\circ}$$\qquad(d)\;None\;of\;these$