I think it is C. But im not sure
Answer:
I would say A.
Explanation:
It IS one of the longest sentences, but that is not the point.
I would say it's too broad because there will probably have to be more details than just this sentence, for example.
''Processed foods can cause health issues for people with weak immune systems, or people with diabetes. They can cause high blood pressure, or high cholesterol.''
Hope this helps.