Explanation:

• Body’s defenses against infections will weaken: Proteins are vital for immune function, so a lack will weaken immunity.
• Production of hormones needed by the body will be impaired: Many hormones are proteins or rely on proteins, so deficiency affects their production.
• Conversion of heat by the body cells into energy, which sustains life, will be impaired: This statement is incorrect because proteins are not primarily responsible for converting heat to energy; carbohydrates and fats primarily fulfill this role.
• Body’s growth will be impaired: Proteins are crucial for growth and tissue repair, so lack of them will impair growth.
• Correct Answer: Conversion of heat by the body cells into energy, which sustains life, will be impaired