A breeder wants to set up a program to produce zebrafish with long fins. Having long fins is a dominant trait compared to the short-finned wild type. Before she can market her zebrafish, she needs to perform a test cross on the long-finned fish she plans to use as a breeder. How can she tell whether her fish are homozygous or heterozygous for the long-finned trait? A. Cross the long-finned fish with short-finned fsh; if three-fourths of the offspring are long-finned and one-fourth are short-finned, the long-finned parent is homozygous. B. Cross the long-finned fish with short-finned fish; if three-fifth of the offspring are long-finned and one-fourth are short-finned, the long-finned parent is homozygous. C. Do several test crosses between the long-finned fish and short-finned fish; if the offspring are always long-finned, the long-finned parent is probably homozygous.