One Method of Determining the Location of the Center of Gravity

Multiple Choice

One method of determining the location of the center of gravity of a person is to weigh the person as he/she lies on a board of negligible weight supported by two scales.In one example the height of the man is 190 cm;when he lies on the board,the left scale reads 450 N and the right scale reads 390 N.The center of gravity of the man relative to his feet on the right is

A) 135 cm.
B) 121 cm.
C) 115 cm.
D) 102 cm.
E) 98 cm.