7. Fill the numbers from $-10 \sim 14$ into a $5 \times 5$ grid such that the sum of the numbers in each row, each column, and each diagonal is the same. What is this sum?
(A)2
(B) 5
(C) 10
(D) 25
(E) 50
7. C.

In a $5 \times 5$ grid, the sum of the numbers in each row, each column, and each diagonal is $S$.

Notice that, no matter how these 25 integers are arranged, their total sum is
$$
\begin{array}{l}
-10-9-8-\cdots+13+14 \\
=11+12+13+14=50=5 S \\
\Rightarrow S=10 .
\end{array}
$$