When preparing a boiler for startup and the boiler is equipped with a modulating combustion control, it is best to
a) set the manual-auto switch to "auto"
b) set the manual-auto switch to "auto" and set the flame control switch in the lowest position
c) set the manual-auto switch to "auto" and set the flame control switch in the highest position
d) set the manual-auto switch to "manual" and set the flame control switch in the lowest position
e) set the manual-auto switch to "manual" and set the flame control switch in the highest position
Answer: D