Which of the following best explains why protein requirements are increased during pregnancy, serious infection, and recovery from surgery or burns?

These conditions cause shifts in body fluids and increased plasma volume, raising demand for circulating proteins to help maintain oncotic pressure.

Each situation raises need for new tissue or immune proteins, increasing amino acid demand for growth, repair, and host defense. 

They stimulate higher rates of hormone and enzyme production, increasing need for amino acids to support expanded metabolic and regulatory protein synthesis.

They elevate overall energy turnover and tissue remodeling, so dietary protein contributes to both energy provision and substrate for reparative processes.