I believe the answer would be Letter
B. Psychology
Answer:
abiogenesis
Explanation:
a (not) biogenesis (coming from other life forms)
Biogenesis would mean that it's coming from other life forms,
Natural selection is a part of evolution (what is there to select?)
Variation is also a part of evolution (not related)
So if it's 20% adenine (A) then it's 20% (T)...because A always pairs with T. That adds up to 40%....60% therefore is G+C...so you'd have 30% Cytosine (C) and 30% Guanine (G).