@cynthia-lee this one is a little tricky, but I think the key line in passage A is "caries formation is affected by carbohydrates' texture and composition..". So while it's true that in general carbohydrates cause more caries due to their texture and composition, it's unlikely that ALL carbohydrates have the exact same texture and composition. Since those are the two factors the passage mentions that affect rate of caries, we can assume that we will have some carbohydrates that cause caries more frequently than others. I hope that helps!
