The correct answer is:
a. increasing the entropy of the universe by giving off heat and generating waste products.
Organisms maintain a high level of organization (i.e., low entropy) internally by utilizing energy from their environment. This process involves the transformation of energy from food, sunlight, etc., into forms that allow them to grow and maintain their structure. In doing so, they release heat and waste products, which contributes to an overall increase in the entropy of the universe, in accordance with the second law of thermodynamics. Thus, while local entropy (within the organism) may decrease, the total entropy (of the universe) increases, consistent with thermodynamic laws.