Concept:The error is in the use of the verb form after "help," which should take the base form of the verb.
Explanation:Part C, "and this reduction can help preventing," is grammatically incorrect.
The word "preventing" should be replaced by "prevent," because after "help" we use the base form of the verb.
Thus, the corrected phrase is "this reduction can help prevent obesity and high blood pressure."
The corrected sentence is: "If daily salt intake is reduced by five to eight
grams, the risk of cardiovascular disease can be lowered, and this reduction can help prevent obesity and high blood pressure."
All other parts of the sentence are correct.
Answer:Option C