Question

choose the correct answer.
if all of the lightbulbs are on, what can we say about the switch?
it is closed.
we cant determine anything about the switch.
it is open.

Explanation:

In a basic electrical circuit, for current to flow and light - bulbs to be on, the switch must be closed. A closed switch provides a complete path for the electric current from the power source (battery) through the circuit (including the light - bulbs) and back to the power source. If the switch were open, there would be a break in the circuit, and no current would flow, resulting in the light - bulbs being off.

Answer:

It is closed.