The menstrual cycle in a normal adult woman is of (in $days$)

Categorize the following animals into those exhibiting menstrual cycle and those exhibiting oestrous cycle.
$I -$ Monkeys,$II -$ Cows,$III -$ Sheep,$IV -$ Apes,$V -$ Humans,$VI -$ Rats,$VII -$ Deer,$VIII -$ Dogs,$IX -$ Tigers
$\text{Menstrual cycle} \quad \quad \quad \text{Oestrous cycle}$

On which day of the menstrual cycle does ovulation occur?

In a $28$-day human ovarian cycle,ovulation occurs on:

What is the menstrual cycle? Which hormones regulate the menstrual cycle?

The following graph shows the relative concentrations of the four hormones present in the blood plasma of a woman during her menstrual cycle. Identify the hormones.