You respond to a service call to a furnace and discover the pilot light is not working. You re-light the pilot and when you release the reset-button, the pilot goes off again. Which of the following is NOT the p ossible cause of the problem?

You respond to a service call to a furnace and discover the pilot light is not working. You re-light the pilot and when you release the reset-button, the pilot goes off again. Which of the following is NOT the p ossible cause of the problem?