The correct option is B 35,000 kJ/kg
Calorific value is measured as the amount of heat produced by burning 1 kg of fuel. It is expressed as kJ/kg.
2.5 kg produces heat = 87500 kJ
1 kg of fuel will produce = 875002.5
= 35000 kJ
Hence, the calorific value of the fuel is 35000 kJ/kg.