For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm3), while the C.V. is same on weight basis (i.e., kcal/kg) ?
A. Propane and acetylene
B. Propane and LPG
C. Sewage gas and gobar gas
D. B.F. gas and coke oven gas