The disproportionately large presence of upper castes' among the urban middle class is an indication that:

Disadvantaged groups are not benefiting from constitutional safeguards 

The caste groups that had access to education under the old system continue to benefit under the new system as well 

Upper castes have migrated in large numbers from rural to urban centers 

Since the opportunities have increased to the disadvantaged groups in rural areas, their number is less in urban areas