A cross of white eyed female and red eyed male drosophila gives red eyed females and white eyed males. Rarely this cross may give all white eyed females and red eyed males. This was found to be due to
1. loss of a sex chromosome
2. non disjunction of X chromosomes in female
3. mutation in female fly
4. mutation in male fly

Options

A. loss of a sex chromosome
B. non disjunction of X chromosomes in female
C. mutation in female fly
D. mutation in male fly

Answer

B