The complete sentence, in this case, is 'thanks to vaccines, the small pox virus has been eradicated' (Option D is correct).
Vaccines are special formulations that may contain antigenic substances in order to trigger immune memory responses in the individual by activating the production of antibodies that bind these antigens in pathogenic agents.
In conclusion, the complete sentence, in this case, is 'thanks to vaccines, the small pox virus has been eradicated' (Option D is correct).
Complete question:
Fill the blank in the sentence. Thanks to vaccines, the _________ virus has been eradicated. Options: common cold; flu; chicken pox; small pox.
Learn more about vaccines here:
https://brainly.com/question/625596
#SPJ1
