What is the midpoint of segment shown below ?
Also, what do they mean by “midpoint of segment”

The midpoint is the middle of the segment, on the segment equidistant from each end.
We compute it by taking the average of the coordinates
[tex]M=\frac 1 2(-3 + -6, 4 + -1) = (- \frac 9 2, \frac 3 2)[/tex]
Choice C
Option: C is the correct answer.
C. [tex](-\dfrac{9}{2},\dfrac{3}{2})[/tex]
We know that the vertices of the mid point C(x,y) of the line segment AB with vertices as A(a,b) and B(c,d) is given by:
[tex]x=\dfrac{a+b}{2},\ and\ y=\dfrac{c+d}{2}[/tex]
Here we are asked to find the mid point of the line segment joining the point (-6,-1) and (-3,4)
Let C(x,y) be the mid point of this line segment.
Hence, we have:
[tex]x=\dfrac{-6-3}{2},\ and\ y=\dfrac{-1+4}{2}\\\\i.e.\\\\x=\dfrac{-9}{2},\ and\ y=\dfrac{3}{2}[/tex]
Hence, the mid point has vertex:
[tex](-\dfrac{9}{2},\dfrac{3}{2})[/tex]