The image provided shows the full reaction and the products of the reaction.
By heating 3-sulfolene, the compound breaks down into SO₂ gas and butadiene. The diene then reacts with the fumarate which is a dienophiles and these two species then undergo a Diels-Alder reaction. The diene reacts with the alkene portion of the fumarate and forms a new 6-membered cyclohexene ring. Since we have trans-fumarate, that leads to two potential products. We form a stereoisomer with stereocenters (1S, 2S) and another with stereocenters (1R, 2R). These two isomers formed are enantiomers. Therefore, the overall product is a racemic mixture of the two enantiomers.
While each individual enantiomer is optically active, the overall product would be racemic and therefore, not optically active.
