Ephedrine—used in dietary supplements and decongestants—is an extract of plants belonging to phylum Gnetophyta.
a) Gnetophyta consists of three genera: Gnetum, Ephedra, and Welwitschia;
b) ephedrine is a compound produced by members of the genus Ephedra.
c) Phylum Anthophyta, phylum Coniferophyta, phylum Ginkgophyta, and phylum Cycadophyta are incorrect.