K 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. (-1,6) and (5,4) 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. Indicate whether the line through the points rises, falls, is horizontal, or is vertical. (Simplify your answer.) A. The line is horizontal. B. The line is vertical. OC. The line rises from left to right. D. The line falls from left to right.