(c)
When the reactants and catalyst are in the same phase, the catalysis is known as homogeneous.
$2CO(g) + O_{2}(g)\overset{NO(g)}{\rightarrow}2CO_{2}(g)$
In this reaction both reactant and catalyst are in the gaseous phase.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.