Convert the flow-rate from Am3/h to Sm3/h

Consider a compressor (model ABC-Z4).  The compressor has a suction pressure of 3 barg, and a discharge pressure of 6 barg.  The inlet temperature is 15 deg C.  The flowrate of gas to the compressor is 20 Am3/h.

The compressor is driven by a motor.  The motor operates at 2930 rpm, and is connected to the compressor by a speed reducing gear, with a ratio of 2.96543877567578433736853:1.

(hint, you can ignore the number of digits after the decimal point, I do not want to you consider changes in speed for this question).

Gas A is propane (molecular mass = 44)

Gas B is air (molecular mass = 29)

Gas C is natural gas (molecular mass = 17)

Gas D is helium (molecular mass = 4)

1. Of these 4 gases, which one requires the largest motor to drive the model ABC-Z4 compressor?

2. Why?

3. Convert the flow-rate from Am3/h to Sm3/h (assume standard conditions are 1.01325 bar abs and 15 deg C).