"if two lines intersect, then the intersection is a point." what is the hypothesis? two lines intersect
intersection is a point
points have intersection
intersection happens at a point

Hypothesis is: Intersection happens at a point

Step-by-step explanation:

A hypothesis in science is a suggested explanation of something that has a consequence or leads to an occurrence.  Usually it will be written in the form of an "if and then" statement.

Such statement explains what would occur, or follow if the possibility enunciated in the "if" part of the statement happens.

In this case the hypothesis is that if there is intersection of lines, it has to occur at a point. Therefore the closest to that statement among the options given in the problem is the last one: "Intersection happens at a point"