Answer
C, $\frac{2}{3}$
Work Step by Step
The slope equation is m=$\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$,
and it's given that $x_{1}$=-5, $x_{2}$=1, $y_{1}$=3, $y_{2}$=7 so
m=$\frac{7-3}{1-(-5)}$=$\frac{4}{6}$=$\frac{2}{3}$
Therefore the answer is C