What should be the pre - heating temperature of aluminium job for gas welding?

A. 200 Degree Centigrade - 400 Degree Centigrade

B. 250 Degree Centigrade - 400 Degree Centigrade

C. 300 Degree Centigrade - 400 Degree Centigrade

D. 350 Degree Centigrade - 400 Degree Centigrade

Correct Answer: 250 Degree Centigrade - 400 Degree Centigrade