If $x=\log_ea$ Maximum possible fractional error in x is

Question

$\begin{array}{1 1} (a) \;\large\frac{\Delta x}{x}=x \frac{\Delta a}{a} \\ (b) \;\large\frac{\Delta x}{x}=x^2 \frac{\Delta a}{a} \\ (c) \;\large\frac{\Delta x}{x}=\frac{1}{x} \frac{\Delta a}{a} \\ (d) \large\frac{\Delta x}{x}=\frac{1}{x^2} \frac{\Delta a}{a} \end{array} $