Given below are two statements: One is labelled as Assertion A and the other is labeled as Reason R:
Assertion (A) : The first stage of gametophyte in the life cycle of moss is protonema stage.
Reason (R) : Protonema develops directly from spores.
In the light of the above statements, choose the most appropriate answer from the options given below:

Assertion (A) correctly identifies the protonema stage as the initial phase of the gametophyte in mosses. Protonema is a filamentous structure that arises from the germination of moss spores.

Reason (R) is also accurate. Protonema develops directly from spores through germination. When a moss spore lands on a suitable substrate and conditions are favorable, it germinates to form a thread-like protonema structure, which eventually gives rise to the leafy gametophore or thallus of the moss plant.

Therefore, both the assertion and reason are valid and related, providing an accurate description of the moss life cycle.