When a wheat variety of red karnels (homozygous for two nonallelic and independent dominant ganes) is crossed with white kernelled wheat (homozygous for two recessive nonalleic independent genes), the phenotypic ratin in `F_(2)` generation would be
A. `9:7`
B. `1:10:4:1`
C. `1:4:6:4:1`
D. `1:2:4:2:4:2:1`