The correct option is A True
When two lines intersect, the sum of one angles from both the pairs of vertically opposite angles, is 180∘
Now, if one pair forms an acute angles, say θ be the acute angle.
Then the other angle formed be ϕ
hence, θ+ϕ=180
ϕ=180−θ
But, θ is an acute angle, hence ϕ is an obtuse angle.
hence, the other pair of vertically opposite angles will be formed by obtuse angles.