What is the correct structure for 1,3-butadiene?

1,3-butadiene is a diene, which means it has two double bonds in its structure. The "1,3" in its name indicates that the double bonds are located at the first and third carbon atoms of a four-carbon chain. In this case, the structure must incorporate double bonds between the carbons at these positions.

The correct structure, CH₂=CH-CH=CH₂, demonstrates that there are double bonds between the first and second carbons, as well as between the third and fourth carbons, accurately reflecting the name "1,3-butadiene." Each carbon atom in the structure maintains the appropriate number of bonds to hydrogen, ensuring that the overall formula conforms to that of butadiene (C4H6).

Other options do not depict the correct arrangement for 1,3-butadiene. For example, the structure that features a triple bond or only one double bond does not represent the required positioning and quantity of double bonds in the molecule. Thus, the first option is the correct representation of 1,3-butadiene.