The current in the bulb will stop flowing:

if the circuit is broken

The correct answer is option 2. if the circuit is broken.

When we say "the circuit is broken," it means that there is an interruption in the path that the electric current needs to follow in order to complete its circuit. In an electrical circuit, current flows from the power source (such as a battery or a power outlet), through the conductive material (like wires), and then through the load (such as a light bulb or an appliance), before returning to the power source.

If there's a break in this path, such as an open switch or a disconnected wire, the flow of electrons is interrupted, and the current stops. As a result, any device or component in the circuit that relies on the flow of electricity will stop functioning until the circuit is repaired and the path for the current is restored.