A seems most probable.
Oceans are also deeper and larger then Seas.
Body parts supplied by vein or artery.
a.) Hepatic artery - liver
b.) Carotid artery - Brain, neck, and face.
c.) Thoracic aorta - Thorax
d.) Aorta - the Main artery supplies blood to down parts of the body from the heart.
e.) Cranial vena cava - Cranium
f.) Caudal vena cava - Tail.
Answer:
I think it explains that the DNA molecules are double helix with alenine and thymine paired together
Elements in the first row (hydrogen and helium) will have outer electrons in the first energy level. Their principal quantum number is 1. Elements in the second row (lithium through neon) will have valence electrons in the second energy level with a principal quantum number of 2.