The correct option is C One male gamete fuses with the egg cell, another male gamete fuses with polar nuclei and vegetative cell forms the pollen tube.
In a pollen grain, there are usually two cells - the generative cell and the vegetative cell.
Generative cell further divides to give rise to two male gametes while the vegetative cell gives rise to the pollen tube.
One of the male gamete fuses with the female gamete and the other fuses with the polar nuclei.