The primary purposes of insulation include
1. Retaining heat in hot lines
2. Preventing corrosion of metal surfaces
3. Preventing high temperature in power plant buildings
4. Preventing injury to personel
a) 2, 3, 4
b) 1, 2, 3
c) 1, 3, 4
d) 1, 2, 4
e) 1, 2, 3, 4
Answer: C