For $H_2$
W = 0.184g
T = 290K at pressure P and Volume V
$PV = \large\frac{0.184}{2}\times R\times290$ ---------(1)
For gas
W = 3.7 g
T = 298 K at Pressure P and Volume V
$PV = \large\frac{3.7}{m}\times R\times298$-------(2)
By (1) and (2)
$\large\frac{0.84}{2}\times R\times290 = \large\frac{3.7}{m}\times R\times298$
m = 41.326
Hence answer is (b)