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 plane a door [title] Open and close the door to locate the trouble spots. [step] Mark such spots with a pencil on both sides of the door so that you can maintain the door's symmetry. [title] Remove the door from the frame. <sep> (A) [step] Flip the door over to get more clearance in both directions. [title] Apply some primer on the door to seal out wrinkles. (B) [step] Turn the door's knobs clockwise. Work the knobs clockwise to open the door enough to find the problem spots. (C) [step] Unscrew the hinges from the door face. Tape the screws to the hinges to avoid misplacing them, and set them aside. (D) [step] Remove the two wind chimes from their stand by removing them from the frame. [substeps] To prevent damage to the frame, loop each of the wind chimes onto a triangle with a small piece of duct tape instead of a screw.
Student:
C