A package for nonprescription products designed to prevent the addition of foreign material is best described as being?

The package for nonprescription products that is designed to prevent the addition of foreign material is best described as tamper-evident. This type of packaging includes features that indicate whether the product has been altered or contaminated in any way after it has left the manufacturer's control. Tamper-evident packaging can include seals, labels, or other indicators that make it obvious if someone has attempted to access the contents of the package, thus ensuring the consumer's safety and the integrity of the product.

Tamper-evident packaging is particularly important for nonprescription products because these items may be purchased and used by a wide range of consumers who need assurance that the product is safe to use. This type of packaging helps to build consumer trust and confidence.

While other types of packaging, such as child-resistant or moisture-resistant, focus on specific aspects of safety or product integrity, they do not specifically address the prevention of foreign material addition in the same way that tamper-evident packaging does.