Question

what happens when you push the button of a doorbell?
the electromagnet becomes stronger.
the current going through the doorbell rapidly switches directions.
the switch is closed, completing the circuit.

Explanation:

When you push a door - bell button, it is a simple switch. Pushing it closes the electrical circuit, allowing current to flow and making the door - bell ring. The electromagnet strength is not directly related to just pushing the button, and the current does not rapidly switch directions when the button is pushed.

Answer:

The switch is closed, completing the circuit.