The correct option is A Water gas
The mixture of CO and H2 is called water gas.
Hydrogen is made in large quantities in an inexpensive manner
by passing steam over red-hot coke. This yields water gas, which is
an important industrial fuel with a high calorific value. When it burns,
it yields a lot of energy!
This doesn't yield pure hydrogen because of CO, which is pesky
and difficult to remove.