The correct option is A.
When using crane at a construction site, it is required that:
1.A poster should be posted at the job site with an illustration of the hand signals that every operator and personnel working with the crane and around the crane must know.
2. Hand signals for crane and derrick operators should be those set by the American National Standard institute customize for the type of crane in use.<span />
        
             
        
        
        
Answer:
chemical equivalent of an element is the value obtained by dividing the atomic weigh of the given element by valency 
 
        
             
        
        
        
My answer is D. All the above :)