Consider the following statements for a pressure vessel which is subjected to internal pressure
1. Radial stress at inner radius is always zero.
2. Radial stress at outer radius is always zero.
3. The tangential stress is always higher than other stresses.
4. The tangential stress is always lower than other stresses.
Which of the statements given above are correct?
(a) 1 and 2 (b) 1 and 4
(c) 2 and 3 (d) 2 and 4