Concept:Assimilation is the process by which absorbed nutrients are converted into molecules that form part of the consumer’s body.Explanation:Digestion breaks down food into simpler substances.Absorption moves digested nutrients into the blood or body fluids.Assimilation is the use of these absorbed nutrients to build new cellular molecules and tissues in the body.Therefore, the conversion of a nutrient into a molecule in the body of a consumer is assimilation.Answer:B. assimilation