The correct answer is d) basal metabolic rate.
The basal metabolic rate (BMR) refers to the number of calories your body requires to maintain essential physiological functions while at rest. This includes processes such as breathing, circulation, cell production, and nutrient processing. Understanding BMR is important because it helps in determining how many calories one needs to consume to maintain, lose, or gain weight. It varies based on several factors, including age, sex, weight, and body composition.