A bottle is labelled pentene. Which molecular formula matches this alkene?
C5H10\text{C}_5\text{H}_{10}C5H10
C4H8\text{C}_4\text{H}_8C4H8
C5H12\text{C}_5\text{H}_{12}C5H12
C6H12\text{C}_6\text{H}_{12}C6H12