On a Field Trip, a Student in a Marine Biology

On a field trip, a student in a marine biology class collects an organism that has differentiated organs, cell walls of cellulose, and chloroplasts with chlorophyll a. Based on this description, the organism could be a brown alga, a red alga, a green alga, a charophyte recently washed into the ocean from a freshwater or brackish water source, or a land plant washed into the ocean. The presence of which of the following features would definitively identify this organism as a land plant?

A) alternation of generations
B) sporopollenin
C) rings of cellulose-synthesizing complexes
D) flagellated sperm
E) embryos