The energy that's given to the body by food is

a. excreted by the body if not used.
b. best obtained by eating high protein.
c. measured in units called calories.
d. a nutrient that's essential for growth and development

absolute strength refers to the maximum force exerted by a body irrespective of body size. relative strength on the other hand is the force exerted by a body in relation to muscle size or body weight.

so the answer is: c. absolute strength measures strength regardless of your body size, while relative strength measures strength adjusted for your weight.