Consider the following statements: Maximum shear stress induced in a power transmitting shaft is
1. Directly proportional to torque being transmitted.
2. Inversely proportional to the cube of its diameter.
3. Directly proportional to its polar moment of inertia.
Which of the statements given above are correct?
(a) 1, 2 and 3 (b) 1 and 3 only
(c) 2 and 3 only (d) 1 and 2 only