To solve this problem, we need to convert 2-butyne to cis-2-butene.$\\$The reaction involves the partial hydrogenation of an alkyne to an alkene.$\\$Given:$\\$• Starting compound: $$2-butyne ($H_3C-C \equiv C-CH_3$)$\\$• Desired product: $$cis-2-butene$\\$The most suitable reagent for this conversion is the Lindlar's catalyst,$\\$which is $$H$_2$ with Pd/C and quinoline.$\\$Explanation:$\\$• Lindlar's catalyst selectively hydrogenates alkynes to alkenes,$\\$ stopping at the alkene stage without further reduction to an alkane.$\\$• It specifically produces the cis-alkene due to the syn-addition of hydrogen.$\\$Therefore, the correct reagent for this conversion is:$\\$Option 2: $H_2,$ Pd/C, quinoline.$\\$This corresponds to the correct option.