Answer
$D$ is correct.
Work Step by Step
In $A$, the square of a number is negative. So, it cannot be a real number.
In $B$, only square of a $0$ is $0$. So, there is only one real solution.
In $C$, There are two real solutions but they are not distinct, since the factors are the same.
In $D$, $11$ can be obtained by squaring $\sqrt{11}$ and $-\sqrt{11}$ that will yield two distinct real solutions for $x$
