Step-by-step explanation:
KE = 1/2*m*v^2
mass won't change
but velocity is
A: the force is pushing against the direction of the object, so velocity is decreasing, so KE is decreasing
B: the F net line is pretty much straight up, which means there is no net force pushing to the left, but velocity is still increasing
Why? Because if you use the pythagorean theorem, the hypotenuse is always longer than the legs.
Note: velocity only ever stays the same if there is no net force (or 0 acceleration), so all four of these are either decreasing or increasing
C: there is a net force to the right, so velocity is increasing
D: There is a net force to the right but velocity is to the left, so velocity is decreasing
Hope I got these right