What components are used to attach the piston to the connecting rod?

The attachment of the piston to the connecting rod is achieved using wrist pins, which are also known as gudgeon pins. These pins are cylindrical in shape and fit through both the piston and the connecting rod, serving as a pivot point that allows the two components to move relative to one another as the engine operates.

The design of the wrist pin is crucial because it must withstand significant forces during the engine's operation, contributing to the transfer of motion from the piston to the connecting rod as the piston moves up and down in the cylinder. This connection also allows the connecting rod to convert the linear motion of the piston into the rotational motion needed for the crankshaft.

Wrist pins are essential in maintaining the alignment and operation of the piston and connecting rod assembly, enabling smooth and effective movement within the engine. Using bolts, bearings, or crankshafts would not accurately describe this critical connection, making the option that emphasizes the role of wrist pins the correct choice.