Answer = C

Reason : It correctly tells why doctor still recommend that pregnant women eat nutritious diet even though babies born to these women develop at least 1 disease. The reason is even with that 1 disorder, these babies are better off than other babies born to women who did not take nutritious diet.

In a Resolve the Paradox question, the answer choice you pick must do justice to both sides of the statement.
In our case the answer choice must satisfy the doc's reco that eating nutritious diet promotes healthy babies and also must satisfy the survey that babies born to mothers who had nutritious diets face atleast one medical problem during their first year.

One way to solve this is to use the rogue element approach.
my assumption is promote health does not mean zero illnesses. atleast one medical problem if it is considered better than 100 medical problems, then sure it promotes health.

This is correctly articulated in C. If not eating nutritious diets leads to say 100 problems and eating nutritious diets reduces this number significantly then it sure does mean that nutritious diet promotes health.

The trap here is that you should not assume promotes health means zero illnesses. anything that improves the condition significantly can be known as promoting the betterment of the condition.

Hope this helps!