The heat needed to warm one gram of water one celsius degree is called a

calorie

Explanation:

Calories are a unit of measure based on the specific heat of water and express the energy power of food.

Most people confuse the term calorie with kilocalorie, the right thing is to express the energy of food in kilocalories (kcal).

- A calorie is the amount of energy needed to raise the temperature of 1 gram of water to 1 ° C.

-  A kilocalorie is the amount of energy needed to raise the temperature of 1 kilogram of water to 1ºC, therefore, one kilocalorie equals one thousand calories.

-  One kilocalorie equals 4,185 kiloJoules.

a electromagnetic waves

option number c is the right answer.