What is meant by the bioavailability of a vitamin in food? the total amount available from plant and animal food the amount absorbed and subsequently used by the body the number of kcal that can be produced from the vitamin the amount that escapes destruction from food processing the number of different chemical forms of the same vitamin?

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.