The number of calories required to keep your body functioning at rest is called:

Correct option is B

The correct answer is (B) basal metabolic rate

Explanation:
• Basal Metabolic Rate (BMR) is the minimum amount of energy (calories) required by the body to maintain basic life functions while completely at rest.
• These vital functions include breathing, blood circulation, cell production, and nutrient processing.

Information Booster:
• BMR accounts for about 60-75% of the total daily energy expenditure for most individuals.
• It varies based on factors like age, gender, body size, and genetics.

Additional Knowledge:
• Metabolism (Option D): The sum of all chemical processes occurring in the body to maintain life, of which BMR is just one component.