Solve. \[ 5 \ln x=-10 \] Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. $x=$ (Type an integer or a decimal. Round to the nearest thousandth. Use a comma to separate answers.) B. The solution is not a real number.

Step 1 ：Divide both sides of the equation by 5 to get \(\ln x = -2\).

Step 2 ：Exponentiate both sides of the equation to get \(x = e^{-2}\).

Step 3 ：Calculate the value of \(x\) to get \(x = 0.1353352832366127\).

Step 4 ：Round the value of \(x\) to the nearest thousandth to get \(x = 0.135\).

Step 5 ：The solution to the equation is \(\boxed{0.135}\).