Step 1: Understanding protein intake in medical conditions.
- Renal failure patients need a low-protein diet to prevent the kidneys from being overloaded and to reduce the buildup of waste products in the blood.
Step 2: Explanation of incorrect options.
- Marasmus (A) and Kwashiorkor (D) are severe forms of protein deficiency where increased protein intake is needed.
- Immunodeficiency (B) generally requires adequate protein intake for immune system function.
Step 3: Selecting the correct option.
- Since renal failure patients require a controlled protein intake, the correct answer is (C) Renal failure.