Answer:

Explanation:
The exponential function and the natural log are inverse functions:
e^ln(x) = x
Using both sides of your given equation as exponents for e, we have ...
e^(ln(3x)) = e^5
From the above, we know that ...
e^(ln(3x)) = 3x
so we can substitute that into the preceding equation to get ...
3x = e^5
Swapping sides of the equal sign gives an equation that matches choice B:
e^5 = 3x