\( \mathrm{A}, \mathrm{B}, \& \mathrm{C} \) are the three angles of a triangle. If \( \mathrm{A}-\mathrm{B}=15^{\circ} \) and \( B-C=30^{\circ} \) . Then \( \angle A \) is equal to-

A \( 65^{\circ} \)

B \( 77^{\circ} \)

C \( 80^{\circ} \)