Which of these statements are correct?

Question

Consider the following statements.                                                          

         1. Principal stresses at the point

         2. Maximum shearing stress at the point

         3. Stress components on any arbitrary place containing the point

         Which of these statements are correct?

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

         (c) 2 and 3                  (d) 1 and 2