Consider the following processing methods for plastics:
1. Transfer moulding
2. Extrusion
3. Thermoforming
4. Caleendering
Which of these are best suited for processing of plastics to their final shape?
(a) 1,2 and 3 only (b) 1,2 and 4 only
(c) 3 and 4 only (d) 1,2,3 and 4