Your question is Stress-Strain Curve Explanation. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Describe and draw a stress-strain curve and explain what it tells you about material behavior.
On the whiteboard, label the axes and identify the elastic, yield, plastic, ultimate-strength, necking, and fracture regions. Explain what the curve reveals about stiffness, strength, ductility, and toughness, and distinguish recoverable deformation from permanent deformation.