Question

if a researcher finds that there is a correlation between secondhand smoke and childrens asthma, they know for sure that _____.
secondhand smoke causes childrens asthma
secondhand smoke does not cause childrens asthma
prenatal exposure to smoking leads to asthma
asthma and secondhand smoke have some connection

Explanation:

Correlation indicates a relationship or connection, not causation. Just because there is a correlation between second - hand smoke and children's asthma, it means there is some connection, not that one causes the other. Prenatal exposure is not mentioned in the context of the correlation described.

Answer:

asthma and secondhand smoke have some connection