Step 1: Maximize the function.
The given function is \( f(x) = \frac{\log x}{x} \). To find the maximum, differentiate with respect to \( x \):
\[
f'(x) = \frac{1}{x} \cdot \frac{1}{x} - \frac{\log x}{x^2}
\]
Set \( f'(x) = 0 \) and solve for \( x \).
Step 2: Conclusion.
The maximum value of \( f(x) \) occurs at \( x = e \), and the maximum value is \( \frac{1}{e} \), corresponding to option (B).