Agroup of students performing an experiment collect euglena samples from a pond and keep them in darkness in a vessel containing pond water which would be the conclusion for this experiment? a) the euglena cells remain alive because they are completely heterotrophic and feed on the organic matter present in the pond water. b) the euglena cells die because they are completely autotrophic in nature and are unable to create food in the absence of sunlight. c) the euglena cells, which are both autotrophic and heterotrophic, remain alive even in the absence of sunlight because they