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 paint masonry walls [title] Remove any flaked or peeling paint from the masonry. [step] If the wall has already been painted, you need to remove any old paint that is loose, peeling, or flaking away. On an exterior wall, this is most efficiently done with a sandblaster. <sep> (A) New paint must be removed from the wall first, gently scraping around the edges with a rat-tail tail reciprocating scraper. This is most often done on exterior paint walls that are still meant to protect it from debris. (B) In areas where a sandblaster would be too messy and cumbersome, loose paint can be removed with a stiff wire brush and a paint scraper. [substeps] Failing to remove loose and peeling paint can result in the paint flakes mixing in with your fresh coat of paint and marring the finish. (C) [substeps] Make sure to turn off the water. Do not flush the wall down the drain. (D) If there is a paint-resistant paint strip still clinging to the wall, it may be painted to the wall as well, but not directly under it. [substeps] Using a sandblaster may be wise, but if the paint is not taking off, it may be better to start by sanding lightly.
Student:
B