A chemical supplier has classified four compounds in its catalogue. Three classifications are correct and one is incorrect.
| Compound | Molecular formula | Classification |
|---|---|---|
| P | C5H10\text{C}_5\text{H}_{10}C5H10 | Not a hydrocarbon |
| Q | C3H8O\text{C}_3\text{H}_8\text{O}C3H8O | Not a hydrocarbon |
| R | C2H4Cl2\text{C}_2\text{H}_4\text{Cl}_2C2H4Cl2 | Not a hydrocarbon |
| S | CO2\text{CO}_2CO2 | Not a hydrocarbon |
Which one of these corrections should be made?
Change compound R to ‘hydrocarbon’.
Change compound S to ‘hydrocarbon’.
Change compound P to ‘hydrocarbon’.
Change compound Q to ‘hydrocarbon’.