As a general rule, when you are following a vehicle, what is the minimum time/space you would leave in front of you?
A.4 seconds
B. 5 seconds
C. 3 seconds
D. 8 seconds

i don't think so. although it would be nice. i am pretty sure that was an option an update or two ago. i guess they want you to stay 14 forever. haha.

only #2 represents an object at rest on a table.

in #1, there is no normal force due to the table; the object is accelerating downward.

in #3, the vertical forces are not balanced; the object is accelerating downward.

in #4, neither the vertical nor the horizontal forces are balanced. the object is accelerating upwards and to the right.