What effect did jonas salk's discovery have on society?
it increased the cost of medical treatment
it made vaccination without a needle possible.
it nearly eliminated a dreadful disease,
it improved medical x-ray technology

C

Explanation:

Jonas Salk developed a vaccine that almost eliminated Polio as a threat. Whole buildings prier to his time were devoted to housing the victims of Polio (one of whom was FDR) who had to make their skeletal systems work with the new restrictions.

The answer is C

trachea, alveoli, lung capillaries, arteries