What role do pawls play in an extension ladder?

Pawls are critical components in the operation of an extension ladder, specifically designed to secure and hold the extended fly sections in place. When the fly sections of the ladder are extended for use, the pawls engage with notches or rung placements, locking the sections into position and preventing them from retracting or sliding back down under the weight or force applied during operation. This feature ensures that firefighters have a stable and secure ladder to work from while performing rescue or firefighting activities. The effectiveness of pawls directly contributes to the overall safety of ladder use, as it allows for a reliable and sturdy setup necessary in emergency situations.

In this context, the role of pawls is essential for maintaining the structural integrity of the ladder once it has been extended, making option B the accurate choice.