The center is the midpoint of the diameter.
The coordinates of the midpoint:
[tex](\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2})[/tex]
(x₁,y₁) - the coordinates of one endpoint
(x₂,y₂) - the coordinates of the other endpoint
[tex](-4,3) \\
x_1=-4 \\ y_1=3 \\ \\
(1,6) \\
x_2=1 \\ y_2=6 \\ \\
\frac{x_1+x_2}{2}=\frac{-4+1}{2}=\frac{-3}{2}=-1.5 \\
\frac{y_1+y_2}{2}=\frac{3+6}{2}=\frac{9}{2}=4.5[/tex]
The coordinates of the center are (-1.5,4.5) - the answer is A.
