The correct answer is C) First tap your elbow with one hand, and then proceed to use regular signals. This is the correct answer because the standard hand signals for crane operations require the crane operator to first be given a signal to indicate that the whip line (the small line used to control the movement of the load) is to be used. Tapping the elbow is the established signal to indicate that the whip line should be used, before proceeding with the regular hand signals to direct the movement of the load. The other options are incorrect because they do not follow the established crane signal protocols. Tapping the head (A) or using a thumb-up motion (B) are not the recognized signals for using the whip line. Option D describes a generic motion signal but does not specify the initial elbow tap required to indicate the use of the whip line.