a. Haploid and is found in mosses

b. Diploid and is found in liverworts

c. Diploid and is found in pteridophytes

d. Haploid and is found in pteridophytes

A)Correct option – A

B) Explanation of correct option –

● It is a thread-like chain of cells that forms the earliest stage of development of the gametophyte.

●Moss spores germinate to form an alga-like filamentous structure called the protonema.