What does "conformance testing" assess in aggregate quality?

Conformance testing is specifically designed to determine whether a substance, in this case, aggregate, meets predetermined criteria regarding its physical properties. These criteria can include parameters such as gradation, moisture content, density, and strength, which are essential for ensuring the aggregate will perform adequately in a given application, especially in construction and road building. This testing is fundamental as it verifies compliance with standards set by industry regulations or project specifications.

While aesthetic appeal and local availability might be considerations in the overall procurement and application of aggregates, they are not part of the conformance testing process. Additionally, the ability to withstand extreme temperatures relates more to the material's durability under certain environmental conditions rather than its compliance with the specified physical property criteria. Thus, the focus of conformance testing on assessing physical properties makes option B the correct choice.