This triangle has an exterior angle labeled ∠A. All of the interior angles are labeled correctly. image e5f63f7bbab74b7f95dc5e8fc7f71331

Which statement about the exterior angle is correct?

A
It is 120° because 40°+80°=120°.

B
It is 140° because it is supplementary to 40°.

C
It is 50° because it is complementary to 40°.

D
It is 60° because 60°+40°=100°.