2025 Fermat Problem 11

Twelve lightbulbs are in a row. All lightbulbs are initially turned off. Angie flips the switch for every 2nd lightbulb. Then Bilal flips the switch for every 3rd lightbulb. Finally, Chenxhui flips the switch for every 4th lightbulb. At the end of this process, how many lightbulbs are turned on?

\textbf{(A)}\ 5\quad \textbf{(B)}\ 6\quad \textbf{(C)}\ 7\quad \textbf{(D)}\ 8\quad \textbf{(E)}\ 9

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Fermat contests here.