Final answer:
The midpoint of the line segment AB is located at (1/2, -5/2).
Step-by-step explanation:
The midpoint of a line segment can be found by taking the average of the x-coordinates and the average of the y-coordinates of the two endpoints.
For the given points A(-1,-9) and B(2,4), the midpoint is ((-1+2)/2, (-9+4)/2), which simplifies to (1/2, -5/2).
Therefore, the correct answer is a) 1/2, -5/2.