A- 
The pedigree chart depicts that parents are normal but offsprings are affected which indicates that it is present in recessive form in parents. Inheritance of phenylketonuria has recessive autosomal characters hence option A is correct. While in inheritance of colour blindness & inheritance of hypertrichosis, both males & females are not affected & both have sex linked inheritance characters hence options inheritance of colour blindness & inheritance of hypertrichosis is ruled out.