The correct option is C
Uniform tax rates across the country
One of the advantages of GST is that it integrated different tax lines such as Central Excise, Service Tax, Sales Tax, Luxury Tax, Special Additional Duty of Customs, etc. into one consolidated tax.
It prevents multiple tax layers imposed on goods and services. Thus leading to uniform tax rate across the country.
The tax rates on services appreciated from 14% to 18%
States which are the destination of goods get the SGST share of the GST while states with production base lose out on its SGST.