Researchers have suggested that people can be divided into chronotypes. A chronotype identifies an individual as a(n)

morning type or an evening type

Explanation: According to research, a chronotype identifies an individual as a morning type or an evening type. By definition, a chronotype is the natural disposition of an individual to be more alert or lethargic at different times of the day (especially in the morning or in the evening), depending on a variety of factors associated with circadian rhythms (the 'internal body' clock that regulates the 24-hour cycle of biological processes in both animals and plants).

c. heat from the poles back down towards the equator.