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. \( (-9,-4) \) and \( (-9,9) \) Select the correct choice below and fill in the answer box within your choice. A. The slope is B. The slope is undefined.

**B. The slope is undefined.** The line through the points \( (-9, -4) \) and \( (-9, 9) \) is **vertical**. --- **Explanation:** - Both points have the same \( x \)-coordinate (\( x = -9 \)), which means the line is vertical. - A vertical line does not have a defined slope because the change in \( x \) is zero, leading to division by zero when calculating the slope. - Therefore, the slope is **undefined**, and the line is **vertical**.