What is the acceptable level of emissions for vehicles inspected in Maine?

The correct choice indicates that vehicles inspected in Maine must comply with both state and federal emissions standards. This dual requirement ensures that vehicles not only adhere to nationwide regulations set by the Environmental Protection Agency (EPA) but also meet specific criteria mandated by the state of Maine.

This comprehensive approach is crucial because federal standards establish a baseline for emissions control, aiming to enhance air quality across the country. Meanwhile, state standards may be more stringent to address local environmental concerns and public health issues. By requiring compliance with both, Maine aims to ensure that vehicles on its roads are not only legal but also contributing to cleaner air and better environmental outcomes. This is particularly important in urban areas where vehicle emissions can significantly impact air quality and public health.

Therefore, options that imply adherence to only one set of standards fail to recognize the regulatory framework that encompasses both federal and state requirements, while the suggestion of no emission standards would ignore established environmental protections that are critical for public health and safety.