The correct answer is: C. Either I or II is implicit.
The statement “This drink can be had either as it is, or after adding ice to it” does not explicitly state that people differ in their preferences, nor does it explicitly state that some people will get attracted to the drink as it can be had as it is. However, both of these assumptions are implicit in the statement.
The statement implies that there are two ways to consume the drink, and that people may prefer one way over the other. This suggests that people differ in their preferences. Additionally, the statement implies that the drink is enjoyable both ways, which suggests that some people will be attracted to the drink.
Therefore, either assumption I or assumption II is implicit in the statement.