A 14-year-old girl comes to the office for a health maintenance evaluation. She is concerned that she has not yet started her menstrual cycle. Her height has increased by 3 inches since her last visit 1 year ago, and her weight is up by 10 pounds. On physical examination, the physician notes a general enlargement of her breasts and areola. Examination of her genital area reveals pubic hair that is coarse and dark and extends past the medial border of the labia. Which of the following is the most likely diagnosis?
a) Constitutional delay
b) Dysfunctional uterine bleeding