Which of the following statements are correct regarding the female reproductive cycle?
$A$. In non-primate mammals,cyclical changes during reproduction are called the oestrus cycle.
$B$. The first menstrual cycle begins at puberty and is called menopause.
$C$. Lack of menstruation may be indicative of pregnancy.
$D$. Cyclic menstruation extends between menarche and menopause.
Choose the most appropriate answer from the options given below.

• A
  $A, C$ and $D$ only
• B
  $A$ and $D$ only
• C
  $A$ and $B$ only
• D
  $A, B$ and $C$ only