Please what’s the last one i don’t have much time left

correct option is C

The function F(x) for 0 < x < 5, the block's initial velocity, and the value of Ff. 

Step-by-step explanation:

The total work done = P.E + K.E

K.E = 1/2mv^2

The speed V depends on the position:

0 < x < 5

Also, since work done = F × distance x

The workdone also depends on F(x)

The net force = 0 that is

F + fr = 0

Where fr = frictional force.

Therefore the best option for the hypothesis of work done will be;

The function F(x) for 0 < x < 5, the block's initial velocity, and the value of Ff.