Two lines intersect at a point, forming ​ ∠1 , ∠2 , ∠3 , and​ ​ ∠4 ​ .

∠1 and ∠3 are vertical angles.

∠2 and​ ​ ∠4 are vertical angles.

m∠1=70°

What is the measure of ​​ ∠2 ​?

A. 20

B. 70

C. 90

D.110