The correct option is B
The tax already paid on inputs, which can be reduced at the time of paying tax on output.
Explanation:
Option (a) is incorrect: Goods and services on which 0% GST is applicable are called NIL Rated Supplies.
Option (b) is correct: Input tax credit means at the time of paying tax on output, we can reduce the tax already paid on inputs.
Option (c) is incorrect: Goods and services which are exempt from payment of GST are called as Exempt Supplies.
Option (d) is incorrect: Goods or services which are exported or supplied to SEZ are called Zero-Rated Supplies. The suppliers making Zero-rated supplies are entitled to claim refunds, but are not called as Input Tax Credit.