The correct option is A Bryopsida
The greatest species diversity in Bryophytes is found in the Mosses, with estimates of the number of species ranging from 10,000 to 15,000. Higher-level classification of the Mosses remains unresolved with a considerable difference of opinion on the names of the major groups. More than 95% of Moss species belong to the Bryopsida making it the most diverse class among the bryophytes.