What is the length of time hair remains in the growth phase before resting?

The length of time hair remains in the growth phase, known as the anagen phase, before entering the resting phase, called the telogen phase, typically ranges from 3 to 7 years. During the anagen phase, hair actively grows and can reach significant lengths, influenced by factors such as genetics and health. This phase is crucial for achieving longer hair, as it dictates how long hair can grow before it transitions to a phase where it stops growing and eventually falls out. Thus, the indicated range of 3 to 7 years reflects a common duration for this growth period in human hair, making it the correct answer. Other options do not accurately represent the typical duration of the hair growth cycle.