Final answer:
After reflecting the line segment with endpoints (7,5) and (10,1) across the line y = -x, the transformed coordinates become (-5,-7) and (-1,-10), which corresponds to Option B.
Step-by-step explanation:
When a line segment is reflected across the line y = -x, you effectively switch the x and y coordinates and then change their signs; this is because reflecting over the line y = -x is the same as rotating the point 90 degrees clockwise around the origin and then reflecting it over the x-axis. The line segment with endpoints (7,5) and (10,1) will then have its endpoints transformed into (-5,-7) and (-1,-10) after the reflection. Therefore, the correct pair of coordinates after the reflection is Option B: (-5, -7) and (-1, -10).