Solve this following

$\frac{\pi}{4}-\frac{1}{2} \log _{\mathrm{e}} 2$

$\frac{\pi}{2}-\log _{\mathrm{e}} 2$

$\frac{\pi}{2}-\frac{1}{2} \log _{\mathrm{e}} 2$

$\frac{\pi}{4}-\log _{\mathrm{e}} 2$