Answer;
Retinohypothalamic path
A small branch of the optic nerve, known as the retinohypothalamic path extends directly from the retina to the SCN.
Explanation;
The SCN is an abbreviations for suprachiasmatic nucleus or nuclei; which is a region in the hypothalamus. that is responsible for controlling circadian rhythms.
Retinohypothalamic path is a neural input pathway that extends directly from the retina to the SCN.
The answer to this is Gonads.
(15) Label 1 is D
(16) Label 2 is A
(17) Label 3 is B
(18) Label 4 is C
It explodes
hope this helps lol
