Which hormone is secreted at the time of parturition

$I.$ Sleep-wake cycle   $II$. Body temperature   $III$. Pigmentation    $IV$. Metabolism   $V$. Defence capability

All of the above written activities are influenced/regulated by

Gametokinetic factor is

Iodine is associated with

$GnRH$ stimulates _______ to release _______.

Figure shows human urinary system with structures labelled $A$ to $D$. Select option which correctly identifies them and gives their characteristic and/ or functions.