d
We have the bulk modulus formula as$:$
Bulk Modulus $=\frac{\text { Pressure }}{\text { Strain }}=\frac{p}{\left(V_{0}-V_{n}\right) / V_{0}}$
For an adiabatic process, the bulk modulus is given by
$k=-\frac{V \Delta p}{\Delta V}=\gamma p$
adiabatic bulk modulus $=\gamma p$
At NTP, $p=1.013 \times 10^{5} N / m^{2}$ and $\gamma=1.4$
Hence Bulk modulus $=1.013 \times 10^{5} \times 1.4 \approx 1.4 \times 10^{5} N / m^{2}$