The mammary glands are paired structures that contain the glandular tissue and variable amount of fat. The correct sequence of tissues involved in synthesis and flow of milk are

The nerve cells, brain and spinal cord or central nervous system develops from embryonic

When both $LH$ and $FSH$ attain peak level in the menstrual cycle ?

$A$ : Corticotrophin releasing hormone is a part of the clock that establishes the timing of birth.
$R$ : The signals for parturition originate from the fully developed foetus and placenta which induce mild uterine contractions called foetal ejection reflex.

Study the flow chart. Name the hormones labelled as $A, B, C, D$ at each stage.

$A \quad B\quad C \quad D$