Pollination in Lotus is carried out by

Lotus has bisexual flowers but anthers and stigma mature at different times so self pollination doesn't occur. Thus, Lotus is cross-pollinated by beetles. Beetles are attracted to the Lotus flower by the odour of the nectar. Beetle enter the flower at night and stays there for the whole night. The flower opens in the morning and beetle visits another flower at night. Thus, as the beetle visits different flowers, pollen from one flower are transferred to the stigma of different flowers because pollen get attached to the body of the beetles. Hence, this type of cross-pollination occurs in Lotus by means of insects i.e. beetles. So, the correct answer is C.