Definition: 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".
Input: [header] How to clean a garden sprayer [title] Finish on an empty tank. [step] Plan ahead with your herbicide or pesticide so that you're only filling the tank with as much of the liquid as you need. Spray plants a second time if you need to use up excess herbicide since almost all herbicides are approved to be sprayed twice. <sep> (A) [substeps] Dump the excess liquid into a bucket and pump until it's completely gone. Add more liquid if you need a little extra incentive. (B) [substeps] You can also opt to use an ammonia-based liquid. Usually, ammonia poisons plants, making it possible to obtain some chemicals without covering up a clean tank. (C) [title] Dispose of any liquid remaining in the sprayer. [step] Contact your local health department or environmental agency to find a safe way to dispose of this liquid. (D) [title] Fill the reservoir after you've reached 20 to 40 psi. [step] Whenever there is enough liquid in the reservoir, it should fill just as fast.
Output:
C