Hello There!
This is called the "IRIS"
The iris is the colored part of they eye and it's responsible for focusing light onto the cornea.
You should get rid of any distractions so you can focus.
Option D is correct.
A synapse is the opening between neurons that neurotransmitters pass through.
B) Photosynthesis The Sun is the ultimate source of all energy in the universe. Plants being the main primary producers or autotrophs, use solar energy to make their own food through photosynthesis, thus converting energy into the organic matter that can be consumed by all organisms. They form the basis of almost all food chains from where consumers derive their food.
