If a researcher finds that there is a correlation between secondhand smoke and children's asthma, he knows for sure that a. secondhand smoke does not cause children's asthma b. children exposed to smoke in utero often get asthma c. asthma and secondhand smoke have some connection d. secondhand smoke causes children's asthma

d. secondhand smoke causes children's asthma

Explanation:

The second hand smoke is the smoke that is produced during indoor smoking. Children who breath in the secondhand smoke can have more frequent and severe attacks of asthma. These children are also susceptible to diseases such as pneumonia, bronchitis, poor functioning of the lungs and other problems related to breathing.