You are lifting a 5-ton weight with a single whip rove on a swinging boom set at an angle of 20° to the horizontal. Use the formula for the size of a shackle with a safe working load and determine the minimum size shackle that should be used to secure the head block to the boom?

A
1 3/8 inch
B
1 1/2 inch
C
1 3/4 inch
D
1 7/8 inch
E