Do I calculate as follows:

A) (This would be true for Single Phase)
57A * 208V = 11856VA

even though i think this is the formula for 3p
B)
x in VA/(208V*1.732)= y in amps PER phase

If B) is correct then it would seem that C) would be correct...

C)
57A * 208V * 1.732 = 20,534.59VA PER phase