The three pieces of evidence that establish the credibility of the claim of beginning the immunization practice would be:
B). He tested a vaccine.
D). He won many awards.
E). Others continued his work.
A claim is described as a key argument that the author proposes to the readers.
The claim is presented along with necessary evidence to validate it and establish credibility among the readers.
In the given situation, the above details back the idea that Jenner has been the cause for beginning and the awareness of the program called 'immunization' as thought the concept, moved with testing, and eventually successfully achieved the goal.
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