Which of the following is a primary purpose of emissions testing for vehicles?

The primary purpose of emissions testing for vehicles is to ensure that they meet environmental standards. This process is crucial for maintaining air quality and minimizing pollutants released into the atmosphere. By testing emissions, regulatory agencies can enforce compliance with established limits on harmful substances, such as carbon monoxide, nitrogen oxides, and particulate matter. This helps protect public health and the environment by reducing the overall impact of vehicle emissions on air quality.

The other options do not capture the primary goal of emissions testing. While increasing resale value may indirectly occur if a vehicle is certified as emissions compliant, it is not the primary motivation for these tests. Similarly, emissions testing does not directly influence insurance premiums, although some insurance providers may consider a vehicle's compliance with emissions standards when determining rates. Lastly, identifying mechanical faults unrelated to emissions does not fall under the main objectives of emissions testing, which is focused on compliance with environmental regulations.