Final answer:
The anagen phase is the stage of hair growth in which a hair spends the most time, lasting from 2 to 7 years.
Step-by-step explanation:
The hair growth cycle consists of several stages, including the anagen, catagen, and telogen phases. Out of these, the anagen phase is the stage where the hair spends the most time. During the anagen phase, cells divide rapidly at the root of the hair, leading to the growth of hair. This phase can last anywhere from 2 to 7 years, significantly longer than the other phases of the hair growth cycle. The catagen phase is a transitional stage lasting about 2 to 3 weeks, and the telogen phase is a resting period that lasts for about 2 to 4 months before the cycle restarts with the anagen phase.