Feather colour in parakeets is controlled by two genes. For one pigment gene, the B allele produces blue colour and the b allele does not produce any colour. For the other pigment gene, the Y allele produces yellow colour and the y allele does not produce any colour. Any genotype containing at least one B allele and one Y allele will produce a green parakeet.

Which of the following parental genotypes could produce offspring with the four different colour patterns?

A. BBYy \times BbYy
B. BbYY \times Bbyy
C. bbYY \times bbyy
D. Bbyy \times bbYy