Salk inactivated polio vaccine is distinguished from the Sabin oral polio vaccine by:
A. representation of the three poliovirus strains
B. ability to allow gut replication of virulent virus strains
C. composition consisting of whole virus versus purified subunits
D. cold-adapted versus egg-adapted virus mutants
E. ability to prevent viremia and spread into the CNS
I need an explanation of whether why each choice is right/wrong.