At atmospherice pressure, 2 g of water having a volume of `2.00 cm^3` becomes `3342 cm^3` of steam when boiled. The latent heat of vaporisation of water is `539 cal//g` at 1 atm. The amount of heat added to the system is
A. 539 cal
B. 1078 cal
C. 3342 cal
D. 6684 cal