Given below are two statements. One is labeled Assertion(A) and the other is labeled Reason(R).

Assertion (A): The first stage of gametophyte in the life cycle of moss is the protonema stage.
Reason (R): Protonema develops directly from spores produced in a capsule.
In light of the above statements, choose the correct answer from the options given below.
 

Both Assertion (A) and Reason (R) are accurate, and Reason (R) correctly explains Assertion (A).

In the life cycle of mosses, the protonema is the initial, filamentous stage of the gametophyte generation. It develops directly from spores produced in the sporangium (capsule) of the parent sporophyte. The spores are released from the sporangium and, under suitable conditions, germinate to form the protonema. The protonema later gives rise to the mature gametophyte, which produces male and female gametangia (antheridia and archegonia) for sexual reproduction.

So, Reason (R) accurately describes how the protonema stage is initiated from the spores produced in the capsule (sporangium), and it is the first stage of the gametophyte in the moss life cycle.