How did darwin develop his theory of evolution?

pea plants and some other shii idk bro

not the best question format lol but what i think might as scale color is controlled by a single gene with two alleles, the green allele and the yellow allele. when moths that are homozygous for green scales are mated with moths that are homozygous for yellow scales, 100% of the offspring have green scales.

i think that c)gold was found there

but i am not sure