Find the slope of the line passing through the pair of points or state that the slope is undefined. Then indicate whether the line through the points rises, falls, is horizontal, or is vertical. \( (6,-9) \) and \( (-9,-9) \) Select the correct choice below and, if necessary, fill in the answer box within your choice. A. The slope is OB. The slope is undefined.

To determine the slope of the line passing through the points \( (6, -9) \) and \( (-9, -9) \), follow these steps: 1. **Calculate the Change in \( y \) (Δy):** \[ \Delta y = y_2 - y_1 = -9 - (-9) = 0 \] 2. **Calculate the Change in \( x \) (Δx):** \[ \Delta x = x_2 - x_1 = -9 - 6 = -15 \] 3. **Determine the Slope (m):** \[ m = \frac{\Delta y}{\Delta x} = \frac{0}{-15} = 0 \] Since the slope \( m = 0 \), the line is **horizontal**. **Answer:** **A. The slope is 0. The line is horizontal.**