Explanation:

Let’s break it down:

- Five boys (p, q, r, s, t) sit in a row facing south. Five girls (A, B, C, D, E) sit in a row behind them facing north. The rows face each other.

- A is sitting at one end.

- q is just left of s (so “... q s ...” in boys’ row), and q faces E.

- B and r are diagonally opposite each other.

- t faces C, and C is just right of A.

So, visualize:

- If A is at the leftmost end (from her view, since she faces north), then C is next to her. So, girl row: A, C, ___, ___, ___.

- t faces C. So t must sit opposite C.

- q is left of s. q faces E.

- So, we have to fit E in a spot opposite q.

Check diagonals: B and r are diagonally opposite. Let’s say:

Girls:  A   C   ___   B   E

Boys:      p   t   r   s   q

But q needs to be left of s. So flip q and s:

Boys:      p   t   r   q   s

Now, q is left of s. q faces E. E is at the right end; q is also at the right.

- C is next right of A? Yes.

- t faces C? Yes.

Now, diagonals: B and r. Girls' B is in the fourth seat; boys' r is in third seat. Those are diagonally opposite.

Now, about the pair options in the question:

- Ct: C and t are directly opposite, not diagonal.

- Eq: Also face to face, not diagonal.

- Ap: A and p are in the first seat of their rows, directly opposite, not diagonal.

- Dp: D (must be in the middle girl seat), p (leftmost boy), those are diagonally opposite, yes.

So, the diagonally opposite pair among the options is Dp (D and p).

> Option 4, Dp, is correct.