Teacher:In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".
Teacher: Now, understand the problem? Solve this instance: [header] How to use a fluoride rinse [title] Look for a fluoride rinse. [step] There is a difference between a fluoride rinse and a mouthwash. Some mouthwashes do contain fluoride, but you should purchase a fluoride rinse over a general mouthwash if you want the fluoride benefits. <sep> (A) [substeps] The goal is to clean the surface of your teeth before a fluoride rinse. Most mouthwashes contain fluoride and other ingredients that will clog your mouth, making it difficult to rinse thoroughly. (B) [substeps] Ask your dentist if there is a fluoride rinse that they recommend. They may also have fluoride rinse samples at their office. (C) If your mouth still feels painful when you introduce fluoride rinse, you might consider changing your personal mouthwash routine. [substeps] Look for anything with fluoride in it. (D) [substeps] Fluoride rinses are commonly used to treat throat pain, but even a saltwater rinse will not work for you if your throat is sore. Always read the product information when buying a fluoride rinse.
Student:
B