Answer: b) 0
The void ratio will become the maximum void ratio when cohesionless soil present in its loosest form.
i.e. , e = e(max.)…(i)
The formula of density index is,
ID = (e (max.) – e)/(e(max.)-e(min.))…(ii)
From equation (i) & (ii), we will get,
ID = (e (max.) – e(max.))/(e(max.)-e(min.))
ID = 0