Answer:
D!!
Explanation:
all the above they are all contributed!!
An innovative way was an improvised vaccination.
This consisted of smearing open cuts of healthy people with substances taken from wounds of sick people (for example sick from smallpox) in the hope that they will undergo a mild version of the disease and when the disease catches them, not die.
The risk was that they could get seriously ill, but the advantage was that on average, they had better survival chances than without this "vaccine"
He told them they too could have a mustache as cool as his
