The basic reason why shafts are made of steel and its alloys is:

Question

 Consider the following statements:

         The basic reason why shafts are made of steel and its alloys is:                       

1. The shaft is subjected to normal and shear stresses.
2. The shaft stress alternates with respect to time
3. The shaft is subjected to pure compressive stress.
4. The shaft is subjected to stress of constant intensity

Which of these statements are correct?

(a) 1 and 2(b) 2 and 3

(c) 3 and  4                     (d) 4 and 1