Which one of the following equations correctly gives the relationship between the specific gravity of soil grains (G) and the hydraulic gradient (i) to initiate 'quick' condition in sand having a void ratio of 0.5?

Which one of the following equations correctly gives the relationship

1.	Which one of the following equations correctly gives the relationship between the specific gravity of soil grains (G) and the hydraulic gradient (i) to initiate 'quick' condition in sand having a void ratio of 0.5?
A.	G = 0.5i + 1
B.	G = i + 0.5
C.	G = 1.5i + 1
D.	G = 1.5i - 1
Answer» D. G = 1.5i - 1