During the warm up period of a heating boiler, the main burner goes out. The operator should:
a. Shut down the boiler immediately purge the boiler and restart it
b. Shut down the boiler, close the fuel valves and determine the cause of the problem
c. Try to re-light the burner immediately
d. Check the altitude gage to ensure there is enough water in the system
e. Clean the burner, purge the boiler and restart it
Answer: B