🔍 Key Concepts

• Wrist pin (gudgeon pin) connects the piston to the small end of the connecting rod and allows it to pivot • Differentiate between piston, connecting rod, and piston pin in the illustration • Focus on the cross‑section view inside the piston rather than external bolts or bearings

💭 Think About

• First, find the piston in one cylinder and trace the connecting rod upward; what solid part actually passes sideways through the piston? • Compare that sideways pin with the crankpin at the crankshaft: which one is at the piston end, not the crank end? • Look at each labeled option on or near the piston and ask: is this the part that forms the pivot between rod and piston, or is it something else like the piston skirt or crankpin?

✅ Before You Answer

• Verify that the chosen label is on the small end of the connecting rod, inside the piston • Confirm the labeled part is a short horizontal cylindrical pin passing through the piston, not the vertical rod or crankshaft • Make sure you are not mistaking the crankpin (at the crankshaft) for the wrist pin (at the piston)