Which statement is correct?
A) Using expensive hair products can enhance the mitotic growth of hair cells within the shaft.
B) A hair shaft is made of varying densities and consistencies of keratin.
C) All hairs have the same growth cycle until mid-life.
D) Carotene is the major pigment that colors hair shafts.
E) Any hair loss signifies a medical condition, which should be checked by a doctor.