Explanation:

Let's break down each statement and see how the boxes can be arranged:

- Eight boxes: P, Q, R, S, T, U, V, W (from bottom 1 to top 8).

- Box U is a prime-numbered box but not box 5. Prime numbers in 1-8 are 2, 3, 5, 7, so U is 2, 3, or 7.

- The number of boxes above W is equal to the number below U.

- So if U is in position x, then W is in position 9 - x.

- Box number of box S is twice the box number of box V.

- So possible pairs: (V=1, S=2), (V=2, S=4), (V=3, S=6), (V=4, S=8).

- Box P is just above box U.

- Box Q is two boxes above box T.

Let’s solve stepwise:

1. If U=3 (prime, ?5):

- Then W=6 (number above W = number below U: 2 below U, so put W such that 2 above W, W at 6).

2. S and V. If S=4, V=2 (since U could be at 3), S=6 would conflict with W.

3. P just above U suggests P=4, U=3.

4. Q two above T can be anywhere unassigned.

Arranging:

1: V

2: S

3: U

4: P

5: T

6: W

7: Q

8: R

Q (7), T (5): Q is two above T.

So, box just above box T (position 5) is W (position 6).

Option 3: W

- Correct answer is Option 3: W

- U is at position 3 (prime, not 5), P just above at 4

- Q (7), T (5): valid, as Q is two above T

- Box S (2), V (1): fulfills S = 2*V

- W's position fits the condition for boxes above and below

- Hence, W is just above T