In carrying out his breeding studies, Mendel determined patterns of inheritance by examining characters that had which of the following properties?

A. The characters each were controlled by a single gene.
B. They were controlled by loci that were (or behaved as if they were) on different chromosomes
C. All of the listed responses are correct.
D. It was possible to isolate true-breeding varieties for each trait.
E. The traits varied in an either-or fashion