A, collision because you need 2 people to collide to have a collision not only one thing/person.
Us students should time how long we study for and how long and frequent our breaks are because one begin we can get burntout for many hours at a time with no break , 2 it makes you more productive it sets you a specific time you do this and that and it gets done efficiently with out losing track of time , 3 having breaks in between studying helps you retain the information better and more importantly not make you more frustrated with the work
Im not a great person with time management but i tried lol
C serving on a jury (not A because thats the executive branch, not B because thats not a branch and not D because of the same reason as B)