An analyzer has two true breeding lines of rabbits, both of which are albino. Albinism is recessive in both lines. When the researcher crosses the rabbits, all of the offspring have the wildtype phenotype. Therefore:   
A)Albinism results from different loci in each mutant line.   
B)Albinism is controlled by the same loci in both mutant lines.    
C)There is not enough information to answer this question.   
D)The rabbits used to make the cross were heterozygous for the albinism locus.