Given below are two statements One is labelled as Assertion A and the other is labelled as Reason R.

Assertion (A): The first  multicellular gametophyte in the life cycle of moss is protonema stage 

Reason (R): Protonema is the creepy, filamentous stage formed from germination of spore  .

In the light of the above statements, choose the most appropriate answer from the options given below 

The assertion A is true. The fi rst stage of gametophyte in the life cycle of moss is the protonema stage. The protonema is a thread-like structure that develops from the germinating spore of the moss and grows into a branching system of fi laments. The protonema stage is followed by the development of leafy gametophores that bear the sex organs of the moss. The reason R is true. The protonema develops directly from the spores produced in the capsule, which is the sporangium  of the sporophyte generation in mosses. The capsule contains diploid cells, which undergo meiosis to produce haploid spores. These spores are released and can germinate under favourable conditions to form the protonema, which is the first stage in the development of the haploid gametophyte generation in mosses. Both A and R are correct and R is the correct explanation of A.