Inability of functional pollen of one species or genera to effect fertilisation of the female of related species or genus is called

Answer: Option A

The inability of functional pollen of one species or genera to affect the fertilisation of the female of a related species or genus is called Cross-incompatibility.
CI has been defined as any relationship (or its absence) between pollen and pistil which prevents hybrid zygote formation in crosses between two fertile species.
Incompatibility is a common means of controlling breeding behaviour among plants, and has been an important factor in evolution.