What defines a trench in terms of dimensions?

The correct definition of a trench in terms of dimensions is a feature that is less than 15 feet wide and can be 20 feet or more deep. This understanding is crucial in emergency response and safety operations because trenches can pose significant risks during rescue or recovery efforts due to their depth and potential for collapse.

In the context of rescue operations, knowing that trenches meet specific width and depth measurements helps responders assess the situation effectively and apply the appropriate safety measures and equipment. Dimensions provide clear guidelines for evaluating whether a situation involves a trench, and this knowledge is vital for ensuring safety protocols are followed during rescue attempts.

Defining a trench as having a width greater than its depth or being shallow overlooks the critical parameters established for identifying such hazards. Similarly, the notion that it must be at least 20 feet across does not align with the standard criteria used to categorize trenches, which emphasizes their narrow width rather than an expansive measurement. Therefore, the definition provided through the correct option is aligned with established safety standards in the field.