When using a 15-foot ladder secured against a wall, how far can a person safely reach out to one side?

When using a ladder, safety and stability are key considerations. The person on the ladder should not lean out too far to maintain balance and prevent the ladder from tipping. The reach of a person on a ladder can be reasonably extended to a distance equal to their arm's length while ensuring they remain in a secure and stable position.

Choosing to extend as far as one's arm's length allows for optimal safety; it prevents overreaching, which can lead to loss of balance and potential falls. While a person could attempt to reach further, it would significantly increase the risk of an accident. Thus, the correct answer reflects a safe practice for working on a ladder, emphasizing the importance of maintaining stability and control while performing tasks at height.