Mendel's Experiments with Garden Peas Differed from Those of Other

Mendel's experiments with garden peas differed from those of other plant hybridizers of the time in that Mendel:

A) studied true-breeding strains instead of poorly defined material.
B) focused on a small number of easily contrasted traits instead of a large number of more complex traits.
C) quantified his results and looked for statistical patterns instead of simply noting the presence or absence of a trait among a group of offspring.
D) performed no crosses between strains, whereas other hybridizers did.
E) studied true-breeding strains, focused on a small number of easily contrasted traits, and quantified results.