The correct answer would be option A. Leafy gametophytes. The feature that differentiates mosses from liverworts and hornworts are the leafy gametophytes. A gametophyte is a multicellular haploid generation which is involved in the process of alternation of genes along with a diploid generation called as sporophyte.
So,
There is a scientific consensus that life exists on other planets
and
The scientists only studied one meteorite
The first one because the other ones don't make sense, and because it is a scientific consensus. The latter because they only studied one, and imagine if they studied other ones...
The Answer to the question is C
