What is the primary function of anticoagulants?

Anticoagulants primarily function to thin the blood, which helps prevent the formation of harmful blood clots. These medications are essential in the management of various medical conditions where there is a risk of clot formation, such as deep vein thrombosis, pulmonary embolism, and certain types of heart conditions. By reducing the blood's ability to clot, anticoagulants enhance blood flow and reduce the risk of complications associated with thrombosis. This is why the correct answer highlights their role in thinning the blood.

The other options describe functions related to completely different areas of medical treatment. For instance, controlling seizures pertains to antiepileptic drugs, treating depression relates to antidepressants, and stopping loose bowel movements involves medications aimed at addressing gastrointestinal issues. Each of these serves distinct therapeutic purposes that are unrelated to the action of anticoagulants.