c
We know that the bulk modulus is,
$\mathrm{B}=-\frac{\mathrm{dpV}}{\Delta \mathrm{V}}$
Here $\mathrm{p}=$ Pressure (stress)
$-\frac{\Delta \mathrm{V}}{\mathrm{V}}=\text { Volume strain }$
But liquid is incompressible, so
${\Delta \mathrm{V}=0} $
Hence, ${\mathrm{B}=-\frac{\mathrm{pV}}{0}=\infty}$
or $\mathrm{B}=\infty$ (infinity)