Metabolism encompasses which of the following processes in the body?

The correct choice highlights that metabolism refers to the sum of all chemical processes that occur within the body. This encompasses a wide range of biological activities, including the conversion of food into energy, the synthesis of necessary compounds and molecules, the breakdown of substances, and various biochemical pathways involved in maintaining homeostasis.

Metabolism is divided into two main categories: catabolism, which is the process of breaking down molecules to release energy, and anabolism, which involves using energy to construct components of cells such as proteins and nucleic acids. This broader understanding of metabolism illustrates its essential role in regulating not just drug processing but also how the body manages nutrients, hormones, and waste products.

The other options narrow down the concept of metabolism unnecessarily. Focusing solely on the breakdown of drugs or the absorption of nutrients does not encompass the totality of metabolic processes. Similarly, while hormone production is a significant biochemical activity, it represents just a small aspect of the overall metabolic processes taking place in the body.