Final answer:
The main term in the phrase is 'Basal,' which refers to the basal metabolic rate (BMR), the energy the body needs at rest to maintain vital functions. Factors like age, gender, body weight, and muscle mass influence BMR, and it can adjust to changes in energy intake or increase with exercise.
Step-by-step explanation:
The main term in the phrase 'Low basal metabolic rate' is B) Basal. The basal metabolic rate (BMR) is a measure of the energy expended by the body at rest in a neutrally temperate environment, post-absorption of food. It reflects the minimum energy necessary for maintaining vital bodily functions such as heartbeat, respiration, and kidney function. The BMR comprises a significant part of an individual's total energy expenditure, with about 70 percent going towards maintaining the basic functions of the body's organs, while the remaining energy is allocated to physical activities and thermoregulation.
An individual's BMR is influenced by various factors, including age, gender, total body weight, and muscle mass. For example, athletes typically have a higher BMR due to increased muscle mass. It's also important to note that the body may adjust its BMR in response to changes in energy intake, such as during overeating or undereating, and that exercise can increase the BMR by producing more heat transfer and work.