Alkaptonuria is an inherited condition in humans that affects phenylalanine and tyrosine metabolism, resulting in the production of black-coloured urine.  What deduction can be made about the allele for this condition from the pedigree chart?

A. It is autosomal dominant.
B. It is autosomal recessive.
C. It is X-linked recessive.
D. It is Y-linked recessive.

B

N/A