Consider the following operations:
1. Cutting key ways on shafts
2. Cutting external screw threads
3. Cutting teeth of spur gears
4. Cutting external splines
Those which can be performed with milling cutters would include
(a) 1 and 2 (b) 2,3 and 4
(c) 1 and 3 (d) 1,2,3 and 4