It began in 1790 and ended in 1840
Inside these factories there sometimes were no good ventilation(no windows), many frequent accidents would happen and many children would start working very early maybe starting by the age of 6 yrs old if there parents weren't there to supervise them
I think the answer is c that what i think
The correct answer is option C: someone diagnosed with smallpox.
The person that would have been most grateful for the work of 19th-century scientist Edward Jenner, would be someone diagnosed with smallpox because Jenner was who discovered the first vaccine against the smallpox virus. Moreover, this disease that was widely spread in the 18th century and killed many people.