Consider the following statements:
For a component made of ductile material, the failure criterion will be
1. endurance limit, if the external force is fluctuating
2. fatigue, if the external force is fluctuating
3. yield stress, if the external force is static
Which of the above statements are correct?
(a) 1 and 2 only (b) 1 and 3 only
(c) 2 and 3 only (d) 1, 2 and 3