How does the author of "Edward Jenner and the History of Smallpox and Vaccination” support the claim that the World Health Organization achieved its goal to eliminate smallpox?
(A)by providing information about revaccination and mortality
(B)by giving details about the World Health Assembly report in 1958
(C)by quoting the World Health Assembly’s announcement in 1980
(D)by stating that the group had a global campaign
Further testing proved conclusively that the cowpox virus was able to build immunity against smallpox. Using his theory, similar vaccines were later created for diseases such as yellow fever, mumps, rubella and tetanus.
