Final answer:
Saprophytes are heterotrophic organisms that obtain their nutrition from decomposing organic matter. They use enzymes to break down dead materials which they then absorb. The correct characterization for saprophytes, including saprobes within this context, is heterotrophic.
Step-by-step explanation:
Saprophytes are organisms that derive their nutrition from decaying organic matter. Contrary to plants, they do not have chlorophyll and cannot produce their own food through photosynthesis. Instead, saprophytes, which typically include bacteria and fungi, use enzymes to break down dead organic material into simpler substances that they can absorb as nutrients.
In the context of protists and other organisms capable of nutrient absorption from dead organisms, the correct term would be saprobes, which are a type of heterotroph. Unlike autotrophs that produce their own food through photosynthesis or chemosynthesis, saprophytes and saprobes are heterotrophic as they rely on organic compounds from other organisms for their energy and carbon sources.
Therefore, the answer to the student's question regarding saprophytes is A) heterotrophic. This distinguishes them from autotrophic organisms that use light or chemical energy to synthesize food and from parasitic organisms that derive nutrients at the expense of a living host.