Detailed Instructions: 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".
Problem:[header] How to remove mastic [title] Soak the mastic in hot water. [step] This will only work on some types of mastic, usually in recent homes. It's worth trying first, as wetting the mastic can make other methods safer. <sep> (A) [substeps] Place a piece of paper or cloth on top of the mastic. Pull the paper back gently so the boric acid is exposed to the water. (B) When you submerge the mastic in the bath, it should soak for one to two minutes before it seeps out. [substeps] Soaking in hot water, however, can damage the surface. (C) [substeps] Do not use soap during a mastic soak. It may irritate the mastic deeper than you like, resulting in accidental sores. (D) You should notice the mastic loosening within 20 to 60 minutes. [substeps] Mix the hot water with vinegar or citrus degreaser for extra strength.
Solution:
D