Answer:
The transverse axis of a hyperbola equals the difference between the distances from any point on the hyperbola to each focus. Which is expressed in answer "C" in your list of possible answers.
Step-by-step explanation:
In fact, the definition of hyperbola is that of all point on the plane whose difference between their distance to each focus is a constant.
That constant can be determined in particular when one considers the distance to the actual vertex of the hyperbola (which is on the transverse axis) and whose distance to one of the focii is equal to the transverse axis plus the distance from the vertex to the focus, and from which needs to be subtracted the distance from the vertex to the focus, resulting then in exactly the transverse axis.
