To find the slope of a line passing through the points (-3, 4) and (2, -1), we have to follow the next steps:
1. Use the following equation:

2. Label each of the given coordinates:
(-3, 4) ---> x1 = -3, y1 = 4.
(2, -1) ---> x2 = 2, y2 = -1.
3. Put these values in the previous equation:

Then, the slope is m = - 1 ( Option A).