Industrial cracking of long-chain hydrocarbons from crude oil fractions produces shorter-chain alkanes and alkenes. What is the general formula of the alkenes produced?
CnH2n+2\text{C}_n\text{H}_{2n+2}CnH2n+2
CnH2n\text{C}_n\text{H}_{2n}CnH2n
CnH2n−2\text{C}_n\text{H}_{2n-2}CnH2n−2
CnH2n+1OH\text{C}_n\text{H}_{2n+1}\text{OH}CnH2n+1OH