Answer:
a. -0.9
Step-by-step explanation:
The closer you get to 1, either positive or negative, the stronger the correlation
-.9 is closest to -1, so it has the strongest negative correlation
Check the picture below, so that happens when h = 0.

now, notice, 0 is also a solution, which means at 0 seconds the ball was touching the ground, well, it was kicked "from" the ground, so at 0 seconds it was initially on the ground anyway.