Consider the following statements regarding the choice of conjugate teeth for the profiles of mating gears:
1. They will transmit the desired motion.
2. They are difficult to manufacture.
3. Standardization is not possible.
4. The cost of production is low.
Which of these statements are correct?
(a) 1,2 and 3 (b) 1,2 and 4
(c) 2,3 and 4 (d) 1,3 and 4