The correct answer is B) Extend arm and point finger in the direction to move the boom. This is the correct signal because it is the standard hand signal used to direct a crane operator to swing the crane boom in a specific direction. The extended arm and pointing finger clearly indicate the desired direction of motion for the crane. This is the most direct and unambiguous way to communicate the crane operator's required movement. The other answer choices are not the standard signals for this purpose. Option A describes a circular motion, which would indicate a different crane function. Option C involves a back-and-forth arm motion, which does not clearly indicate the desired swing direction. Option D uses a hand signal that is not typically associated with crane operation.