Which best illustrates how Gregor Mendel used creativity that lead to scientific discovery?

Which best illustrates how Gregor Mendel used creativity that lead to scientific discovery?
A. He noticed that traits were passed on from parents to offspring.
B. He chose a parent generation and carefully studied its traits.
C. He used pea plants to study the patterns of heredity.
D. He observed how specific traits were passed from parent to offspring.