What is used as a catalyst in the Wacker process?

For the following Assertion and Reason,the correct option is
Assertion : For hydrogenation reactions,the catalytic activity increases from Group $5$ to Group $11$ metals with maximum activity shown by Group $7-9$ elements.
Reason : The reactants are most strongly adsorbed on Group $7-9$ elements.

Identify the catalytic reaction in which both reactants are in different phases.

$A$ catalyst is used to

$A$ metal catalyst $(X)$ is used in the catalytic converter of automobiles. This prevents the release of gas $(Y)$ into the atmosphere. What are $(X)$ and $(Y)$ respectively?

Which among the following can be explained by adsorption theory?