JEE Main 2020 Physics question

A litre of dry air at STP expands adiabatically to volume of 3 litres. If = 1.40, the work done by air is : ( = 4.6555) [Take air to be an ideal gas]

• (A)100.8 J
• (B)48 J
• (C)90.5 JCorrect
• (D)60.7 J