Bay Area Rapid Transit (BART) Practice Exam 2025 - Free BART Practice Questions and Study Guide

The correct answer indicates that retractable couplers are located on every car of the train. This is important because retractable couplers are a critical component for ensuring flexibility and safety in train operations. They allow for the safe connection and disconnection of train cars, which enables trains to be modified based on operational needs, such as adding or removing cars as required for different service levels.

Having them on every car maximizes operational efficiency, as all cars can be readily coupled or uncoupled as necessary without having to rely on specific cars equipped with couplers. This enhances the overall versatility and reliability of the train system, supporting various types of operations, whether they are passenger services or freight transport.

In contrast, options that specify limited locations, such as only on passenger cars or freight cars, do not recognize the design's intent and practical use across all types of train cars.