A. Mutation theory
A.
B. Darwinism
B.
C. Lamarckism
C.
D. Genetic drift
D.
Correct Answer: B
সঠিক উত্তর: B
Explanation
ব্যাখ্যা
"Survival of the fittest" is a key component of Darwin's theory of natural selection, emphasizing that organisms best adapted to their environment are more likely to survive and reproduce.