Which one of the following statements is incorrect about the menstrual cycle?

• A
  The first menstruation begins at puberty and is called menarche.
• B
  Lack of menstruation may also occur due to some environmental factors like stress or poor health.
• C
  Corpus luteum secretes large amounts of progesterone,which is essential for the maintenance of the endometrium.
• D
  In the absence of fertilization,the corpus luteum degenerates in the luteal phase and new follicles start developing immediately.