This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
Dose-limiting toxicity of chemotherapeutic agents is 
Select and explain. 
A. Bone marrow toxicity, B. GI toxicity, C. Neurotoxicity, D. Respiratory problems
A: Bone marrow toxicity
Answer: A: Bone marrow toxicity 
Explanation: Depression of bone marrow results in granulocytopenia, agranulocytosis, thrombocytopenia, aplastic anemia. This is the most serious toxicity; often limits the dose that can be employed.