What annual rate of interest compounded continuously is required to triple an investment in 12 years? Round your answer to three decimals.
A. $9.155\mathrm{\%}$
B. $4.794\mathrm{\%}$
C. $5.946\mathrm{\%}$
D. $9.587\mathrm{\%}$

Step 1 ：The formula for continuous compounding is $A=P{e}^{rt}$, where $A$ is the final amount, $P$ is the principal amount, $r$ is the annual interest rate, and $t$ is the time in years.

Step 2 ：In this case, we know that $A/P=3$ and $t=12$ years. We need to solve for $r$.

Step 3 ：We can rearrange the formula to get $r=\ln (A/P)/t$.

Step 4 ：Then we can substitute the known values into the formula and calculate $r$.

Step 5 ：Finally, we need to convert $r$ from a decimal to a percentage and round to three decimal places.

Step 6 ：Final Answer: The annual rate of interest compounded continuously required to triple an investment in 12 years is $\boxed{{\displaystyle 9.155\mathrm{\%}}}$.