Question: Which MongoDB shell command deletes a single document?

1. `db.customers.delete({_id: 1});`
2. `db.customers.drop({_id: 1});`
3. `db.drop.customers({_id: 1});`
4. `db.customers.remove({_id: 1});`

Answer: The correct answer of the above question is Option D:`db.customers.remove({_id: 1});`