Statement (b) is correct regarding Goods and Services Tax (GST) Bill. GST is a single indirect tax aimed at making the country a unified common market. It is imposed on the supply of goods and/or services within India. Multiple indirect taxes that the Central Government or State Governments impose on suppliers and consumers are subsumed by GST. Liquor has been kept outside the goods and services tax for now as it requires a constitutional amendment to bring it under the ambit of the new tax. Petroleum and petroleum products shall be subjected to the levy of GST in future.