Consider that the following materials are usable for manufacturing dies, moulds in investment casting process for the purpose of large-scale production:
1. Aluminum alloy
2. Magnesium alloy
3. Brass
4. Low-carbon steel
Which of the above are correctly usable?
(a) 1, 2 and 3 only (b) 3 and 4 only
(c) 3 and 4 only (d) 1,2,3 and4