In fruit flies, normal wing length, n, is dominant to apterous (no wings), n. also, red eyes, r, are dominant to sepia eyes, r. a particular fruit fly has normal wings and red eyes, but since these are the dominant traits, it is not possible to tell whether this fly is homozygous or heterozygous for these traits simply by looking at it. one way to find out is to perform a test cross. which phenotype represents a fly that should be used in this test cross? a. apterous with red eyes b. apterous with sepia eyes c. normal wings and red eyes d. normal wings and sepia eyes