The expression you provided is \(\sqrt{3x}\).
To express this in simplest radical form, we can check to see if there are any perfect squares for \(3\) or \(x\) to simplify. However, since neither \(3\) nor \(x\) is a perfect square, \(\sqrt{3x}\) is already in its simplest form.
So, the simplest radical form of \(\sqrt{3x}\) is:
\(\sqrt{3x}\)
If you are looking for the multiple choice answers that matches, the correct one is:
\(\sqrt{3x}\)
(assuming this choice is provided among your options).