阅读下列四篇短文，从每小题后所给的A,B,C或D四个选项中，选出最佳选项。
(2013·福州质检)Let's face it.No one drinks diet sodas for the taste.People drink diet sodas in the hope that it will help them lose weight or at least keep them from gaining it.Yet it seems to have exactly the opposite effect，according to a new study.
