The major isolated organic product D) A single chiral alkene. Therefore , D) A single chiral alkene is correct .
The major isolated organic product of the reaction shown is a single chiral alkene. This is because the alkenes produced by the hydrogenation of a chiral alkyne will be diastereoisomers, and one of the diastereoisomers will be more stable than the other.
The more stable diastereoisomer is the one with the largest alkyl groups on the same side of the double bond, which is the trans isomer. In this case, the trans isomer is also the chiral isomer.
The other answer choices are incorrect:
A single chiral alkyne cannot be the product of the hydrogenation of a chiral alkyne. An achiral compound cannot be the product of the hydrogenation of a chiral alkyne.
A racemic mixture is a mixture of two enantiomers in equal amounts. The hydrogenation of a chiral alkyne will produce only one enantiomer, so a racemic mixture cannot be the product.
A different product or a mixture of more than one of the choices in equal amounts is also incorrect. The hydrogenation of a chiral alkyne will produce a single alkene, which will be the trans isomer.