Answer:
C. 4
Explanation:
Given the line that passes through points (-1,-7) and (3,9):
[tex]\begin{gathered} \text{Slope},m=\frac{Change\text{ in y-axis}}{Change\text{ in x-axis}} \\ =\frac{9-(-7)}{3-(-1)} \\ =\frac{9+7}{3+1} \\ =\frac{16}{4} \\ =4 \end{gathered}[/tex]The slope of the line is 4.
The correct choice is C,