The correct option is C pollination
Pollination is the transfer of pollen grains from the anther to the stigma of a flower.
If the pollen from the anther of a flower is transferred to the stigma of the same flower or to another flower of the same plant, then it is called self-pollination.
On the other hand, if the pollen from the anther of a flower is transferred to the stigma of a flower on another plant of the same species, then its called cross-pollination.