The cyclooxygenase isoenzymes COX-1 and COX-2 differ from each other in that: A. They catalyse different pathways in prostanoid biosynthesis B. COX-1 is inhibited by aspirin but not COX-2 C. COX-2 is inhibited by ibuprofen but not COX-1 D. COX-1 is constitutive while COX-2 is largely