The correct option is A haploid and found in mosses
The predominant stage of the life cycle of a moss (bryophyte) is the gametophyte which consists of two stages.
The first stage is the protonema stage, which develops directly from a spore. It is a creeping, green, branched, haploid and frequently filamentous stage.
The second stage is the leafy stage, which develops from the secondary protonema as a lateral bud. It consists of upright, slender axes bearing spirally arranged leaves attached to the soil through multicellular and branched rhizoids. This stage bears the sex organs.
Therefore, protonema is haploid and found in mosses.