Which of the following is produced when propane (c3h8) is combusted completely? (2 points)
a. h2o
b. co
c. o2
d. h2

since it's combustion, combustion normally always involves o2, so it would be c3h8 + o2 = co2 + h2o in the unbalanced form and since co2 isn't on the list, h2o is the only other option.

answer; ///(u-235); ///is the correct