A patient in a cardiological department has arrhythmia. A doctor administered him amyodaron. What is the main mechanism of amyodaron's antiarrhythmic action?

Answer options

1. It activates serotonin receptors
2. It inhibits cholinoreceptors
3. It blocks mostly potassium channels
4. It stimulates histamine receptors
5. It alters myocardium susceptibility to the acetylcholine