To determine the order of body colour, wing size and eye colour genes on the chromosome of Drosophila, which of the following sets of crosses will you perform?

a. Cross 1 - ♂ wild-type heterozygous for normal wings and red eyes x ♀ recessive homozygous for vestigial wings and purple eyes. Cross 2 - ♂ wild-type heterozygous for gray body and red eyes x ♀ recessive homozygous for black body and purple eyes.

b. Cross 1 - ♂ wild-type homozygous for normal wings and red eyes x ♀ recessive homozygous for vestigial wings and purple eyes. Cross 2 - ♂ wild-type homozygous for gray body and red eyes x ♀ recessive homozygous for black body and purple eyes.

c. Cross 1 - ♂ wild-type heterozygous for normal wings and red eyes x ♀ recessive homozygous for vestigial wings and purple eyes. Cross 2 - ♂ wild-type homozygous for gray body and red eyes x ♀ recessive homozygous for black body and purple eyes.

d. Cross 1 - ♂ recessive homozygous for vestigial wings and purple eyes x ♀ recessive homozygous for vestigial wings and purple eyes. Cross 2 - ♂ recessive homozygous for black body and purple eyes x ♀ recessive homozygous for black body and purple eyes.