This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology, Subject name: Medicine
A young child ingests silver polish by accident. The local poison control center states that cyanide is a common ingredient of silver polish.For the above patient with a toxic ingestion or exposure, select the most likely clinical effect. 
Select and explain. 
A. combines with cytochromes and catalase to block hydrogen and electron transport, thus producing tissue asphyxia, B. methemoglobinemia, C. vertigo, hyperventilation, tinnitus, and deafness, D. bone marrow depression
A: combines with cytochromes and catalase to block hydrogen and electron transport, thus producing tissue asphyxia
Answer: A: combines with cytochromes and catalase to block hydrogen and electron transport, thus producing tissue asphyxia 
Explanation: Cyanide is contained in silver polish, insecticides, rodenticides, and some plants. Inhalation of hydrogen cyanide may cause death within a minute; oral doses act more slowly, requiring several minutes to hours. Cyanide combines with cytochromes and catalase to produce tissue asphyxia. The treatment for cyanide poisoning includes the administration of IV sodium thiosulfate, which hastens the transformation of the cyanide to thiocyanate, which is excreted in the urine.