The graph illustrates how stress varies with strain for three wires that have identical linear dimensions but are made from different materials. Which of the following statements are correct? 1. For the same stress, the extension of P is approximately twice the extension of Q. 2. The ratio of the Young modulus of P to that of Q is approximately two. 3. When strain is less than $0.1$, R obeys Hooke’s law.
- A1, 2 and 3
- B1 and 3 only
- C2 and 3 only
- D2 only