a. At the 0.05 level of signicance, is there evidence that the mean microvessel density is higher before the stem cell transplant than after the stem cell transplant? Let p1 be the mean density before the transplant and let p2 be the mean density after the transplant. State the null and alternative hypotheses. Choose the correct answer below. A. H0: en #0 (where p0 =p1 -}12) 3 B. H041D so (where p0 =p1-p2) H13l1|3=0 H15llD>0 C. H0: [in