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 make a fireplace more energy efficient [title] Install a top-sealing chimney damper. [step] Top-sealing dampers replace the fireplace throat damper and are installed at the top of the chimney. The top-sealing damper has a seal that acts like a storm door, keeping the expensive conditioned air inside the house and the outside air-outside. <sep> (A) [substeps] Check the quality of the damper accurately to ensure its old-fashioned texture. Chimney damper versions range from cheap to premade fireplace damper. (B) [substeps] Most water-based fireplaces end with a top-sealing damper damper. This damper exists because the chimney chimney damper is dry enough to withstand collecting ashes and the chimney damper cannot insulate the poisonous air inside. (C) If you have trouble shooting fire, you could use your fireplace damper to replace the chimney damper's damper. [substeps] A top-sealing damper damper can be found at most home improvement stores. (D) This principle works year-round, whether you're heating or cooling your house. This product can be purchased online and is easily installed by either a homeowner or a handyman.
D