This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Accumulation of homogentisic acid causes the following clinical condition: 
Select and explain. 
A. Ochronosis, B. Tyrosinemia, C. Albinism, D. Tyrosinosis
A: Ochronosis
Answer: A: Ochronosis 
Explanation: Ochronosis is the bluish black discoloration of ceain tissues, such as the ear cailage and the ocular tissue, seen with alkaptonuria, a metabolic disorder. Exogenous ochronosis, in which bluish black pigmentation of cailage is noted iatrogenically by exogenous agents, has been seen after exposure to noxious substances, including phenol, trinitrophenol, benzene, and hydroquinone.