The rigth answer is D.
The wavefront or wavefront is an equal phase surface of a wave, i.e., these points have the same travel time from the source. The concept is used to describe the propagation of waves such as sound or electromagnetic radiation (light, radio waves, etc.). In a homogeneous and isotropic medium, in which the waves propagate without deformation, two types of particular waves are distinguished according to whether the wavefronts are spheres (spherical wave) or planes (plane wave).
I would say the answer is b but all of the answer choices could be the correct answer(hope that helps)
Answer:
TEF-thermic effect of food
Explanation:
The thermic effect of food is the energy needed for digestion, absorption, and removal of ingested nutrients. Its magnitude relies on the components of the food consumed: Carbohydrates has 5 to 15% of the energy ingested while Protein 20 to 35% of the energy ingested.
The thermic effect of food can be determined by multiplying the total calories derived from food by 10%. For example, a 2000 calories diet a day will consume approximately 200 calories in digesting the food.