The bulk modulus of elasticity of helium at 1 atmospheric pressure, assuming variation of pressure and volume is adiabatic, is

Question

$$\begin {array} {1 1} (a)\;7.31 \times 10^5\;Pa \\ (b)\;1.73 \times 10^5 \;Pa \\ (c)\;2.5 \times 10^4\;Pa \\ (d)\;5.73 \times 10^7 \;Pa \end {array}$$