The correct option is C right
Let ABCD be a parallelogram.
Consider two adjacent angles ∠A and ∠B
∠A+∠B=1800
[Adjacent angles of parallelogram are supplementary]
∠A2+∠B2=18002
[Angular bisectors of ∠A and ∠B]
∠A2+∠B2=900
If these two angle bisectors meet, it forms a triangle and the sum of the measures of the angles,formed by the angle bisectors and commmon arm, is 900.
⟹ The third angle where these angle bisectors meet will be 900
[Since sum of all the angles of a triangle is 1800]