Protonema is

Explanation-

In mosses, haploid spores formed, after getting dispersed from the capsule may get directly germinated into gametophytic thallus or may form a filamentous structure called protonema bearing adventitious buds to give rise to leafy plant.

Protonema is haploid and is found in mosses.


Final Answer-

So, The correct option is A.
Protonema is haploid and is found in mosses.