Which of the following order of reagent is chosen to prepare 1,3-butadiene from `C_2H_2`
A. `Cu_2Cl_2//NH_4Cl` and `H_2//Pb(BaSO_4)`
B. `NH_4Cl//CuCl` and `H_2//Pd(BaSO_4)`
C. `H_2//Pd(BaSO_4)` and `CuCl//NH_4Cl`
D. `H_2//Pb(BaSO_4)` and `NH_4Cl//CuCl`
