A,C, D.. Those are correct ..
It is a form of natural selection called sexual selection.
Corpus Callosum is a band of thick fibres which connects the hemispheres of the brain.
"The red blood cell<span> survives on average only 120 days. </span>Red cells<span> contain a special protein called hemoglobin, which helps carry oxygen from the lungs to the rest of the </span>body<span> and then returns carbon dioxide from the </span>body<span> to the lungs so it can be exhaled." - hematology.org</span>
The left ventricle is responsible for pumping oxygenated blood throughout the entire body, which requires a lot of work and pressure, hence why it is super thick.
