If $( 2,3,1 )$ Is the Midpoint of the Segment with One Endpoint

Multiple Choice

If $( 2,3,1 )$ is the midpoint of the segment with one endpoint $( 1,3,1 )$ , find the second endpoint.

A) $( 3,3,1 )$
B) $\left( \frac { 3 } { 2 } , 3,1 \right)$
C) $( 1,0,0 )$
D) $( 0 , - 1,3 )$