The tax which was not merged into GST is:

Countervailing Duty
Excise duty
Basic Customs Duty
Purchase tax

The correct answer is: D. Purchase tax

Purchase tax is a tax levied on the purchase of goods and services. It is a consumption tax, which means that it is levied on the final consumption of goods and services, rather than on the production or sale of goods and services.

Purchase tax is a common type of tax in many countries. It is often used as a way to raise revenue and to discourage consumption.

In India, purchase tax was abolished in 2017 with the introduction of the Goods and Services Tax (GST). The GST is a comprehensive indirect tax that replaced a number of other indirect taxes, including purchase tax.

The GST is a destination-based tax, which means that it is levied on the value of goods and services that are consumed in India. The GST is levied at different rates on different goods and services.

The GST is a complex tax, but it is designed to be simpler and more efficient than the taxes that it replaced. The GST is also expected to be more revenue-neutral than the taxes that it replaced.

A. Countervailing Duty is a tax levied on imported goods to offset any subsidies that may have been provided to the producers of those goods in the country of origin.

B. Excise duty is a tax levied on goods produced or manufactured within a country.

C. Basic Customs Duty is a tax levied on imported goods at the time they enter the country.