Assertion : Smaller the organism higher is the rate of metabolism per gram weight.

Reason : The heart rate of a six month old baby is much lower than that of an old person.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

B.

If both assertion and reason are true but reason is not the correct explanation of assertion

The basal metabolic rate (BMR) is the energy requirement of the human body at rest and reflects the caloric needs of the body. It can be determined by total body weight and the amount of muscle mass.

It is inversely related with the weight or volume of an organism, i.e. smaller the organism, higher is the basal metabolic rate and vice versa.

Example, Heart rate of 6- month old baby is 110-112 beats/min. Though, it is higher than normal adult person, but it is lower than the old person.