In a Diploid Individual, One Chromosome Carries a and B

In a diploid individual, one chromosome carries A and B genes, and the homologous chromosome carries different forms (alleles) of these same genes, a and b. If there is a single crossover between these two genes involving non-sister chromatids during metaphase I of meiosis, the resulting four gametes are:

A) AB, AB, ab, ab.
B) AB, ab, AB, ab.
C) AaBb, AaBb, AaBb, AaBb.
D) AB, Ab, aB, ab.
E) Ab, Ab, aB, aB.