The correct option is C 108o
Let ABCD be a parallelogram. Let ∠A and ∠B be its two adjacent angles such that ∠A:∠B=2:3
Let ∠A=2xo and ∠B=3xo
Since adjacent interior angles are supplementary.
∴∠A+∠B=180o
⇒2xo+3xo=180o
⇒5xo=180o⇒xo=1805=36o
∴∠A=2xo=72o,∠B=3xo=108o
Since opposite angles of parallelogram are equal.
∴∠C=∠A=72o and ∠D=∠B=108o