Question

which is the endpoint of a ray? point r point s point t point u

Explanation:

A ray has one endpoint and extends infinitely in one direction. In the given diagram, rays $\overrightarrow{SR}$, $\overrightarrow{ST}$, and $\overrightarrow{SU}$ all start from point S. So point S is the endpoint for these rays.

Answer:

point S