The appropriate answer is 3. Fats. Fat is a triglyceride molecule. Collectively fats form a type of tissue known as adipose tissue. The primary function of fat is energy storage but when concentrated in adipose tissue it provides thermal insulation and also doubles as a shock absorber for vital organs in the body. Nucleic acids transmits genetic information and is used in cellular activities such as protein synthesis. Carbohydrates when broken down provides heat but are not involved in insulating the body.
