B)
Given:
The coordinates of line segment XY is, X (-2,1) and Y (3,6).
The objective is to determine the equation of perpendicular bisector of line segment XY.
Step-by-step explanation:
The equation of perpendicular bisector can be calculated by finding the slope of line segment XY and its midpoint.
Consider the coordinates of XY as,

The slope of XY can be calculated as,

To find midpoint of line 1:
Now the midpoint of the line segment XY can be calculated as,

To find slope of line 2:
Since, the second line is perpendicular to line 1, slope of line 2 can be calculated as,

To find equation of line 2:
Now, the equation of second line can be calculated using the slope and point formula.

Hence, the equation of perpendicular bisector of line segment XY is
y = -x + 4.