How should you signal the crane operator to move slowly?

A
Use one hand to give any motion signal, and place the other hand motionless in front of the hand giving the motion signal.
B
Extend arm with the thumb pointing up, and flex the fingers in and out for as long as the load movement is desired.
C
First tap your elbow with one hand and then proceed to use regular signals.
D
First tap the top of your head with your fist and then proceed to use regular signals.
E