The cross-section of a triangular prism is an equilateral triangle with side $2x\text{ cm}$.

The length of the prism is $d\text{ cm}$.

Let the total surface area of the prism be $T{\text{ cm}}^2$. Given that the volume of the prism is $T{\text{ cm}}^3$, which one of the following is an expression for $d$ in terms of $x$?