Answer: Secondary sources lack medical expertise.
Step-by-step explanation:
You didn't give the passage to the question but I got the passage online which I read and answered the question accordingly.
The passage provided recommendations on determining the reliability of a source or not such as when dealing with the sources that are related to health.
Based on the information given in the passage, the author explains that the evaluation of the data of sources is necessary in order to determine if an information is backed by evidence. The author also explains that secondary sources relies on the interpretation of another person and may therefore lack expertise which implies that secondary sources lack credibility and medical expertise.