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: Surgery
The following statements regarding tissue plasminogen activator are true, except: 
Select and explain. 
A. It is produced by recombinant DNA technology., B. Induction of systemic lytic state is limited with its use., C. It is ineffective in lysing thrombi of myocardial infarction., D. It is a poor plasminogen activator in the absence of fibrin.
C: It is ineffective in lysing thrombi of myocardial infarction.
Answer: C: It is ineffective in lysing thrombi of myocardial infarction. 
Explanation: Tissue plasminogen activator (alteplase) is produced by recombinant DNA technology. It is a poor plasminogen activator in the absence of fibrin. Its specificity for fibrin limits systemic formation of plasminand induction of systemic lytic state. It is given as intravenous bolus for coronary thrombolysis during treatment of myocardial infarction.