To reduces Intravascular clotting and preventing MI

To reduces intravascular clotting and preventing MI, unstable angina and stroke: a. none b. the balance between platelet proctacyclin$$\mathrm{A}2$$and endothelial prostaglandin (PGI2) can be shifted by administration of high doses of aspirin c. the balance between platelet thromboxane A2 and endothelial prostacyclin (PGI2) can be shifted by administration of low doses of aspirin d. the balance between platelet thromboxane A2 and endothelial prostacyclin (PGI2) can be shifted by administration of high-short term doses of aspirin