Continuous self pollination in a species develops

Type of pollination in commelina is

What is indicated by $'A'$ and $'B'$ in the given diagram?

It grows in watery environment but pollination occurs through Insect / air

Self-incompatibility is a device for

$I$. Ensuring cross-pollination

$II$. Preventing self-pollination

$III$. Ensuring self-fertilisation

$IV$. Genetic control for self-fertilisation

Choose the correct statements from those given above