Mary and debra stand on a snow-covered roof. they both throw snowballs with the same initial speed, but in different directions. mary throws her snowball downward, at 30° below the horizontal; debra throws her snowball upward, at 30° above the horizontal. which of the following statements are true about just before the snowballs reach the ground below? (there could be more than one correct choice.)

a. mary's snowball has a greater downward acceleration than debra's snowball.
b. debra's snowball has exactly the same acceleration as mary's snowball.
c. debra's snowball will stay in the air longer than mary's snowball.
d. mary's snowball will stay in the air longer than debra's snowball.
e. both snowballs will take the same amount of time to hit the ground.