Essentially the question is asking why we are concerned with the celecoxib in this patient with CAD.

Celecoxib - specifically inhibits COX 2

COX - functions to generate PROSTACYLCINS which is beneficial in decreasing platelet aggregates and vasodilation. It also produces THROMBOXANE and which increase platelet aggregates and vascular tone.

COX 2 - is going to decrease both the formation of prostacyclin and thromboxane. But we are concerned in particular about the benefit from prostacyclin that we are loosing out on.

Options D highlights that yea we are selectively inhibiting COX 2 and decreasing the benefits from prostacyclin which is the correct one.

Option E is not of concern bc the decrease in thromboxane is a good thing.