Which statement is true regarding customers under 21 renting vehicles?

The statement that customers under 21 must rent up to 'Fcar' vehicle class is accurate due to insurance and liability policies that rental companies follow. Most vehicle rental agencies impose age restrictions based on risk assessments, and individuals under 21 are often seen as higher-risk drivers. As a result, rental companies typically limit the types of vehicles that young renters can access to smaller or less powerful options, generally categorized within the 'Fcar' vehicle class, which represents a more economical choice.

Limiting renters under 21 to the 'Fcar' category helps reduce risk for the rental companies and allows them to provide access for younger drivers, albeit with certain constraints to protect their interests. Other options do not reflect the established policies that influence vehicle rentals by young customers. Specifically, while it can vary by location, many companies do allow renters under 21, and they can indeed be primary renters if they meet the company's requirements.