Given the task definition and input, reply with output. 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".

[header] How to line curtains [title] Select a thermal liner if you'd like to insulate your windows. [step] If your windows are drafty or thin, save on your heating and cooling costs by lining the curtains with a thermal fabric. The insulation will keep heat in your room during the winter while keeping out drafts from the window. <sep> (A) Keep this in mind when selecting your thermal liner. [title] Trim the curtains to the correct length. (B) It will also keep cool air from escaping during the summer months. [substeps] Most thermal liners are made from cotton, polyester, or a blend. (C) [substeps] Unfortunately, there are not many thermal liners available. Some may cost between $20 and $100. (D) Because you only have a window with a thermal liner, you won't need to line the windows and ceiling with thermal fabric. [substeps] Foam inner liner is the base for your lining, and wool fabric insulates your windows from chilling drafts while keeping the curtains closed.
B