imc

Let's set our length to $2$ and our width to $1$. We have our area as $2\ast 1=2$ and our diagonal: $x$ as $\sqrt{1^2+2^2}=\sqrt{5}$ (Pythagoras Theorem) Now we can plug this value into the answer choices and test which one will give our desired area of $2$. * All of the answer choices have our $x$ value squared, so keep in mind that ${\sqrt{5}}^2=5$ Through testing, we see that $2/5\ast {\sqrt{5}}^2=2$ So our correct answer choice is $\boxed{\frac{2}{5}{x}^2}$