What is a primary characteristic of the USDA's role?

The primary characteristic of the USDA's role is setting agricultural criteria. The United States Department of Agriculture (USDA) primarily focuses on the oversight and regulation of various aspects of agriculture, including standards for food safety, quality, and agricultural practices. This encompasses monitoring and establishing guidelines that influence farming methods, production practices, and food processing standards. By setting these criteria, the USDA aims to ensure food security, promote sustainable agricultural practices, and maintain high standards for nutritional quality.

The other options, while related to the broader context of food and health, do not encapsulate the central function of the USDA as clearly as setting agricultural criteria does. For instance, promoting public health, though an important goal, is largely addressed through other federal agencies like the FDA and CDC. Financial regulation of food markets typically falls under the purview of financial institutions and regulations rather than the USDA directly, while implementing education programs for healthcare is more aligned with health departments and educational institutions than with the USDA's core mission.