To determine the slope of the line that passes through the points \( J(-1, -9) \) and \( K(5, 3) \), we use the slope formula:
[tex]\[ m = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]
Here, \((x_1, y_1) = (-1, -9)\) and \((x_2, y_2) = (5, 3)\).
Substitute the coordinates into the formula:
[tex]\[ m = \frac{3 - (-9)}{5 - (-1)} \][/tex]
Simplify the numerator and denominator:
[tex]\[ m = \frac{3 + 9}{5 + 1} \][/tex]
[tex]\[ m = \frac{12}{6} \][/tex]
[tex]\[ m = 2 \][/tex]
Thus, the slope of the line passing through points \( J \) and \( K \) is \( \boxed{2} \).
Therefore, the correct answer is:
D. 2
