The correct answer is (b), White Paper.
A White Paper is a government publication that sets out a policy or proposal. The term is derived from the fact that the paper is typically printed on white paper. White Papers are often used to announce new policies or to explain changes to existing policies. They can also be used to provide information about a particular issue or to justify a particular course of action.
In the context of India, White Papers have been used to announce a wide range of policies, including the introduction of a new tax system, the privatization of state-owned enterprises, and the liberalization of the economy. White Papers have also been used to provide information about issues such as the Kashmir conflict and the relationship between India and Pakistan.
Green Papers, Yellow Books, and Blue Books are also official documents, but they are not as commonly used as White Papers. Green Papers are used to consult with the public on a particular issue. Yellow Books are used to provide information about the government’s foreign policy. Blue Books are used to provide information about the government’s defense policy.