Question

the amount of energy required to raise the temperature of one gram of water by one degree celsius is a
calorie.
joule.
kilocalorie.
measure of density.
measure of light.

Explanation:

A calorie is defined as the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius. A joule is another energy unit, but the specific definition here matches a calorie. A kilocalorie is 1000 calories (raising 1000 grams of water by 1°C). Density and light measures are unrelated to this energy - temperature - mass relationship.

Answer:

A. calorie.