Edward Jenner’s smallpox inoculation experiment was based on an observation by a dairymaid that she could not get smallpox because she had already had cowpox How did Jenner form his hypothesis from this observation

AHe asked what would happen if he deliberately inoculated someone with cowpox fluid from another person

BHe tested different existing inoculations to see which one was most effective in preventing smallpox

CHe observed dairymaids milking cows with cowpox to see if the statement was true before forming a hypothesis.

DHe drew a conclusion about cowpox infection based on the comment he heard from local farmers.