The correct answer is:
Buta-1,3-diene on heating with maleic anhydride would give a Diels-Alder adduct, 1,2-dimethylenecyclohexane-1,4-dione.
The Diels-Alder reaction is a type of cycloaddition reaction that occurs between a diene and a dienophile. The diene is a molecule with two double bonds, and the dienophile is a molecule with a double bond and a reactive group. In the Diels-Alder reaction, the diene and dienophile react to form a six-membered ring.
In the case of buta-1,3-diene and maleic anhydride, the diene is the buta-1,3-diene and the dienophile is the maleic anhydride. The reaction between these two molecules would form a six-membered ring with two double bonds, 1,2-dimethylenecyclohexane-1,4-dione.
The Diels-Alder reaction is a very important reaction in organic chemistry. It is used to synthesize a variety of compounds, including pharmaceuticals, polymers, and dyes.
The other options are incorrect because they do not represent the products of the Diels-Alder reaction between buta-1,3-diene and maleic anhydride.