A sand deposit has a porosity of 1/3 and its specific gravity is 2.5. The critical hydraulic rediant to cause sand boiling in the stratum will be

A sand deposit has a porosity of 1/3 and its specific gravity is 2.5.

1.	A sand deposit has a porosity of 1/3 and its specific gravity is 2.5. The critical hydraulic rediant to cause sand boiling in the stratum will be
A.	1.5
B.	1.25
C.	1.0
D.	0.75
Answer» D. 0.75