Mari created the circular window represented below. She knew that ∠1 and ∠2 were supplementary and that ∠1≅∠3 because they were vertical angles. What must be true about ∠2 and ∠3 ? (Not drawn to scale.) A. ∠2≅∠3 B. ∠2 is complementary to ∠3 C. ∠2 is supplementary to ∠3 D. ∠2 and ∠3 are both right angles