The correct option is D FeS2
A sulphide of iron contains 46.5% of iron by weight.
100 g of sample will contain 46.5 g of iron and 100−46.5=53.5 g of sulphur.
The atomic masses of iron and sulphur are 55.8 g/mol and 32.1 g/mol.
The number of moles of iron =46.5g55.8g/mol=0.8333.
The number of moles of sulphur =53.5g32.1g/mol=1.667
The ratio of the number of moles of iron to the number of moles of sulphur =0.8333:1.667=1:2
Hence, the empirical formula of the sulphide is FeS2.