Consider the following statements:
Thermosetting plastic are
1. Formed by addition polymerization
2. Formed by condensation polymerization
3. Softened on heating and hardened on cooling for any number of times
4. Modulated by heating and cooling
Which of these statements are correct?
(a) 1 and 3 (b) 2 and 4
(c) 1 and 4 (d) 2 and 3