Which of the following catalyst systems is used to reduce unsaturated hydrocarbons to saturated hydrocarbons?

The catalytic hydrogenation of unsaturated hydrocarbons (alkenes and alkynes) to saturated alkanes is most commonly carried out using finely divided nickel as a catalyst in the presence of hydrogen gas at elevated temperature and pressure. This reaction is known as the Sabatier process for industrial hydrogenation, and is also widely used in the hydrogenation of vegetable oils to produce vanaspati. Platinum and palladium are also effective but the question asks about a common catalyst — nickel with H2 is the standard answer.