Concept:
For a real gas,
\[
PV=ZnRT
\]
where
\[
Z=\text{compressibility factor}.
\]
Hence,
\[
n=\frac{PV}{ZRT}.
\]
Mass of gas:
\[
m=nM,
\]
where \(M\) is the molar mass.
Step 1: Calculate the number of moles.
Given,
\[
P=40\ \text{atm},
\]
\[
V=0.4\ \text{L},
\]
\[
T=27^\circ C=300\ \text{K},
\]
\[
Z=0.65,
\]
\[
R=0.082\ \text{L-atm K}^{-1}\text{mol}^{-1}.
\]
Therefore,
\[
n
=
\frac{PV}{ZRT}
=
\frac{40\times0.4}
{0.65\times0.082\times300}.
\]
\[
=
\frac{16}{15.99}
\approx1.
\]
\[
n\approx1\ \text{mol}.
\]
Step 2: Calculate the mass of the gas.
Given molar mass,
\[
M=44\ \text{g mol}^{-1}.
\]
Thus,
\[
m=nM.
\]
\[
m=(1)(44).
\]
\[
m=44\ \text{g}.
\]
Final Answer:
\[
\boxed{44\ \text{g}}
\]
\[
\boxed{\text{Answer = (B)}}
\]