Context: This passage describes the sickle-cell disease trait in humans:

In a group of humans, some individuals have sickle-cell disease and others do not. In this group, the gene for the sickle-cell disease trait has two alleles. The allele A is for not having sickle-cell disease, and the allele a is for having sickle-cell disease.
Josiah, a human from this group, does not have sickle-cell disease. Josiah has one allele for not having sickle-cell disease and one allele for having sickle-cell disease.
Based on this information, what is Josiah's phenotype for the sickle-cell disease trait?
A. Aa
B. not having sickle-cell disease
Answer with the option's letter from the given choices directly.

B