The correct option is C fruit juices
In the given sentence, a comparison is being made between two drinks and not the act of drinking those drinks. 'Coke' is to be compared with 'fruit juices' option B is correct and option D is incorrect. Option A is incorrect, because fruit drinks are different from fruit juices, and we can see that the sentence mentions 'fruit juices'. In option C, 'that' in 'that of fruit juices' is not clear what it refers to, so this option is wrong.