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: Pharmacology
Which of the following statements about oral anti-coagulants is FALSE 
Select and explain. 
A. They interfere with an early step in the synthesis of clotting factors, B. Irrespective of the dose administered, their anticoagulant effect has a latency of onset of 1-3 days, C. Their dose is adjusted by repeated measurement of prothrombin time, D. They are contraindicated during pregnancy
A: They interfere with an early step in the synthesis of clotting factors
Answer: A: They interfere with an early step in the synthesis of clotting factors 
Explanation: Oral anticoagulants inhibit the activation of factor II, VII, IX and X. These do not affect the synthesis of these factors