When n (n ≥ 2) straight lines intersect each other, when the number of intersections is the largest, how many opposite vertex angles are there

When n (n ≥ 2) straight lines intersect each other, when the number of intersections is the largest, how many opposite vertex angles are there

The number of vertices is n * (n-1) / 2, and the logarithm of vertex is twice of that of n * (n-1)

The following statement is correct ()
A. If two angles are equal, then these two angles are opposite vertex angles B. two angles with common vertex are opposite vertex angles C. two angles with common vertex and equal are opposite vertex angles D. if two angles are opposite vertex angles, then these two angles are equal

A. If two angles are equal, then the two angles are opposite vertex angle, which is wrong; B. If two angles with common vertex are opposite vertex angle, which is wrong; C. If two angles with common vertex and equal are opposite vertex angle, which is wrong; D. if two angles are opposite vertex angle, then the two angles are equal, which is correct; so select D

Are two equal angles with common vertex opposite vertex?

Not necessarily
If both sides of the angle are opposite extension lines and the two angles are equal, then they are opposite vertex angles
If not, then they are not on the vertex