Which of the following best describes the effect of mousing on a load?

The choice that accurately describes the effect of mousing on a load is that it secures the load to prevent accidents. Mousing is a technique used in rigging to provide additional safety by securing the ends of rigging components, such as hooks and slings, to ensure that they do not come unhooked or loosen during lifting. This practice helps to reduce the risk of drops or accidents, making it a vital safety measure in various lifting operations.

The other options do not correctly capture the function of mousing. For instance, mousing does not change the inherent weight of a load, nor does it influence the load's structural integrity in terms of strength. Additionally, mousing is not related to the visual or aesthetic aspects of a load; its primary function is to enhance safety and security during the lifting process.