The answer would be hypothalamus.
Hypothalamus is a part of the brain that located below the thalamus (hypo mean "under"). Hypothalamus can control nervous and endocrine system. It was divided into front/anterior, tuberal and back/posterior part. Thirst would be regulated by anterior and posterior part, temperature by anterior part and sexual behaviour by anterior part.
I would choose the option D.
D. It remains tightly coiled at the G1 phase.
I could help if I knew what you needed help with
Pond ecosystem considered as an open ecosystem because pond is always open . There is an interaction of pond with atmosphere , due to which it ecosystem becomes open.
