Final answer:
Anthocerophytes are not classified as gymnosperms (option C). The four major divisions of gymnosperms are conifers, cycads, ginkgos, and gnetophytes, while anthocerophytes are hornworts.
Step-by-step explanation:
The group that is not classified as a gymnosperm is C. Anthocerophytes. Gymnosperms are a diverse group of seed plants that include four major divisions: Coniferophyta (conifers), Cycadophyta (cycads), Ginkgophyta (ginkgos), and Gnetophyta (gnetophytes). Conifers are known for including pines, firs, and redwoods; Cycads are known for their large, divided leaves and presence in tropical regions; Ginkgos are known for their distinctive fan-shaped leaves; and Gnetophytes, which includes plants like Ephedra, share some characteristics with angiosperms but are still classified within gymnosperms.
In contrast, Anthocerophytes, which are not one of these four divisions, are actually hornworts and do not fall under the category of gymnosperms.
Hence, the answer is option C.