The four phyla of the gymnosperms are:____.
a. conifers, cycads, ginkgos, and gnetophytes.
b. mosses, liverworts, club mosses, and hornworts.
c. conifers, monocotyledons, dicotyledons, and cycads.
d. horsetails, true ferns, whisk ferns, and club mosses.
e. monocotyledons, dicotyledons, conifers, and cycads.