What is the maximum number of trailers allowed in a doubles setup?

Answer: B — Two trailers

In a doubles setup, the maximum number of trailers that can be towed is two. This configuration consists of a tractor unit that pulls two trailers connected in tandem. The design of the doubles setup allows for enhanced capacity and efficiency in transporting freight, as it can carry more goods than a single-trailer configuration while still being manageable on the road. Regulatory guidelines specify that doubles can consist of two trailers, and this is recognized in various transportation laws and licensing structures. Exceeding this configuration with three trailers is not permissible for standard doubles operations and would instead fall under triples setups. Thus, the answer accurately reflects the rules governing doubles combinations in commercial driving.