The 'Goods and Services Tax' was proposed by a task force, whose President was

The ‘Goods and Services Tax’ was proposed by a task force, whose President was :

Which of the following taxes are abolished by the Goods and Services Tax?

What has been kept under the purview of Goods and Services Tax (GST)?

Goods and Services Tax (GST) was nationwide introduced in India from which date?

What is the most likely advantages of implementing ‘Goods and Services Tax’ (GST)?