Question

heterotrophs
what is best defined as an organism that \must consume
another living thing to maintain its energy?\
autotroph
heterotroph
producer

Explanation:

An autotroph produces its own food (e.g., plants via photosynthesis). A producer is essentially an autotroph. A heterotroph, as defined in the text, must consume other living things for energy. The description in the question matches the definition of a heterotroph.

Answer:

heterotroph