Which of the following best describes the use of a dig line?

The use of a dig line primarily serves as a guide for excavation limits. A dig line is typically established to delineate the area where excavation or digging may occur, ensuring that workers know the boundaries of their work area and can avoid unintentional damage to adjacent structures or utilities. By clearly marking these limits, the dig line helps to enhance safety on the job site and maintain efficiency throughout the excavation process. It indicates precisely where the earth should be removed and serves as a critical point of reference for anyone involved in excavation activities.

While other choices mention planting, measuring slope, and assessing soil types, they do not accurately capture the primary function of a dig line in the context of excavation activities. A dig line is not used for planting guidance, measuring slopes, or evaluating the types of soil present; rather, it plays a crucial role in defining the parameters within which excavation work should take place.