Answer:
A. Transverse.
Explanation:
We have been given a statement and we are supposed to choose the correct option to fill in the blank for our given statement.
Statement: The line segment that connects the two vertices of a hyperbola is called the ____ axis.
Since we know that the endpoints of transverse axis are known as the vertices of hyperbola, so the line segment that connects the two vertices of a hyperbola is called the transverse axis.
Therefore, option A is the correct choice.