A property logarythms have, is that [tex] Log_{b}[/tex] a = [tex] \frac{Ln a}{Ln b} [/tex], so [tex] Log_{81}[/tex] 3 = [tex] \frac{Ln 3}{Ln 81} [/tex], numbers we can find out with the help of a calculator.
In this case the answer is 0'25, so the solution is B, 1/4.
