At the time of shedding the number of nuclei present in an angiosperm pollen grain is

The correct option is C two or three
In majority of angiosperms, the pollen grains are shed from the anther at the bicelled (2-celled) stage. But in some genera (both the monocots and dicots), the generative cell divides prior to the dehiscence of the anther and pollen grain is shed at 3-celled stage. Approximately 60% species shed their pollen at the 2-celled stage and 40% at 3-celled stage.