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: Medicine
Sinus bradycardia is seen in: 
Select and explain. 
A. Athletes, B. Exercise, C. Thyrotoxicosis, D. Beta adrenoceptor agonist
A: Athletes
Answer: A: Athletes 
Explanation: Sinus tachycardia is associated with a sinus rate of more than 100/min. The various causes are,

Anxiety
Fever
Exercise
Emotion
Anaemia
Thyrotoxicosis
Beta adrenoceptor agonists

Sinus bradycardia is associated with a sinus rate of less than 60/min and is seen commonly in athletes.

Myocardial infarction
Hypothyroidism
Cholestatic jaundice
Raised intracranial pressure
Beta-blockers
Digoxin
Verapamil