Which hardware components are specified for mounting vehicle cylinder brackets?

The correct choice includes bolts, lock washers, and nuts as the specified hardware components for mounting vehicle cylinder brackets. This is due to their reliable strength and ability to securely fasten heavy components, such as CNG cylinders, to a vehicle. Bolts, when used with lock washers, provide a method to prevent loosening due to vibrations and other forces encountered while the vehicle is in motion. Additionally, nuts serve to create a tight connection that maintains the integrity of the mounting over time.

In contrast, the other options do not provide the same level of strength and stability needed for safely securing vehicle cylinder brackets. Rivets and screws may not allow for adjustments or disassembly when needed, while nails are generally insufficient for structural applications of this nature. Fasteners, spacers, and connectors, while potentially useful in various contexts, do not specifically encompass the robust hardware combination required for securely mounting CNG cylinders, making bolts, lock washers, and nuts the most suitable choice.