Carbon atoms stick to catalyst surface in craking processes?

1 - sintring

2 - poising

3 - aging

4 - cocking or fouling

option D - coking or fouling

Explanation:

Coking (not cocking) is the process involving the deposition of small carbon particles (created by simply putting carbon atoms) on a catalyst's accessible surface, leading in a reduction in the area accessible for catalytic activity. This is also sometimes related to fouling catalysts or merely fouling them.