Answer: Option B
:
B
A microsporangium is generally surrounded by four wall layers – the epidermis, endothecium, middle layers and the tapetum. The outer three wall layers perform the function or protection and help in dehiscence of anther to release the pollen, the innermost wall layer is the tapetum. It nourishes the developing pollen grains. Cells of the tapetum are food righ and posses dense cytoplasm and generally have more than one nucleus. They disintegrate to liberate the contents which is absorbed by the developing spores. Outer most layer of the pollen grain is called exine and each haploid pollen grain develops from diploid sporogenous cell in the anther.