Step 1: Calculate the cross-sectional area of the bolt.
\[
A
=
\frac{\pi d^2}{4}
=
\frac{\pi(16)^2}{4}
=
201.06\,\mathrm{mm^2}.
\]
Step 2: Calculate the shear stress.
\[
\tau
=
\frac{P}{A}
=
\frac{40.2\times10^3}{201.06}
\approx
200\,\mathrm{N/mm^2}.
\]
Since
\[
1\,\mathrm{N/mm^2}=1\,\mathrm{MPa},
\]
\[
\boxed{\tau=200\,\mathrm{MPa}}.
\]
Hence,
\[
\boxed{(C)}
\]
is the correct answer.