The signal man assisting the crane operator has one hand occupied and one fist in front of his chest with the thumb pointing outward and is tapping his chest with the heel of his fist. This is the signal to __________.

Correct Answer: Option C — retract the boom

Standard mobile crane and cargo handling hand signals dictate that holding one fist in front of the chest with the thumb pointing outward and tapping the chest indicates the command to retract the boom.