Consider the following statements in connection with thrust bearings:
1. Cylinderical thrust bearings have higher coefficient of friction than ball thrust bearings.
2. Taper rollers cannot be employed for thrust bearings
3. Double row thrust ball bearings is not possible
4. Lower race, outer race and retainer are readily separable in thrust bearings.
Which of the above statements are correct?
(a) 1 and 2 (b) 2 and 3
(c) 3 and 4 (d) 1 and 4