Consider the following characteristics of production jobs
1. Processing of parts frequently in small lots.
2. Need to accommodate design changes of products.
3. Low rate of metal removal.
4. Need for holding close tolerances.
The characteristics which favour the choice of numerically controlled machines would include
(a) 1,2 and 3 (b) 2,3, and
(c) 1,3 and 4 (d) 1,2, and 4