2. Embryo sac is to ovule as _______ is to an anther.a. Stamenb. Filamentc. Pollen graind. Androecium

please explain....

The correct answer is c) Pollen grain

Embryo sac is to ovule as _pollen grain______ is to an anther.

The relationship given in the fill in the blank is about   gametophytes and the part in which they are developed . Embryo sac is female gametophyte which is developed inside ovule ( megasporangium). The same way pollen grain is male  gametophyte which is  developed inside microsporangium present in anthers. Gametophyte is the structure that produces gametes.  Pollen grain produces male gametes inside pollen tube. Same way embryo sac (female gametophyte)  contains female gamete (egg cell) inside it