catalysis Questions

Match the catalyst with the process:Catalyst: (i) ${\text{V}}_2{\text{O}}_5$, (ii) ${\text{TiCl}}_4+{\text{Al(CH}}_3{)}_3$, (iii) ${\text{PdCl}}_2$, (iv) Nickel complexesProcess: (a) Oxidation of ethylene to ethanal, (b) Polymerisation of alkynes, (c) Oxidation of ${\text{SO}}_2$ in manufacture of ${\text{H}}_2{\text{SO}}_4$, (d) Polymerisation of ethyleneWhich of the following is the correct matching?