Consider the following statements regarding a torque converter:
1. its maximum efficiency is less than that of the fluid consuming
2. It has two runners and a set of stationary vanes interposed between them.
3. It has two runners.
4. The ratio of secondary to primary torque is zero for the zero value of angular velocity of secondary.
Which of these statements are correct?
a) 1 and 2 b) 3 and 4
c) 1 and 4 d) 2 and 4