A woman has lately been excessively excitable and irritable and had insomnia. She was prescribed diazepam. What is the main mechanism of action of this drug?

Answer options

1. Beta-adrenergic receptor stimulation
2. Serotonin receptor blockade
3. Muscarinic acetylcholine receptor Stimulation
4. Benzodiazepine receptor stimulation
5. Nicotinic acetylcholine receptor blockade