1 liter of dry air at STP expands adiabatically to a volume of 3 litres. If γ=1.4, the work done by air is (3¹.⁴ = 4.655) (take air to be an ideal gas)
A. 48 J
B. 90.5 J
C. 100.8 J
D. 60.7 J