Lamar Gant, U. S. powerlifting star, became the first man to deadlift five times his own body weight in 1985. Deadlifting involves raising a loaded barbell from the floor to a position at or near the waist. Determine the work done by Lamar in deadlifting 3.03x10^5 g to a height of 77 cm above the ground.
How much work did Mr. Gant do on the barbell during this amazing feat?
A: 3.12 x 10^3 N x m
B: 3.12 x 10^6 N x m
C: 2.29 x 10^5 N x m
D: 3.12 x 10^5 N x m
E: 2.29 x 10^8 N x m
F: 2.29 x 10^3 N x m