I believe it's D. Deoxygenated blood to the lungs.
1.3i hope it helps you
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No. Yes phenotypes are important for example those with longer legs can run faster and hence escape predators
But genes also code for unseen proteins
For example, if a disease is introduced those with long legs won't survive but those who have the genes which code for the complimentary antibody have the ability to kill the pathogen and hence survive.
