Concept:
The Inter-State Council is a constitutional body established under Article 263 of the Indian Constitution to facilitate coordination between the Union and the States.
Step 1: Evaluating Assertion (A).
Assertion (A) is correct. According to Article 263, if at any time it appears to the President that the public interests would be served by the establishment of a Council, it shall be lawful for the President by order to establish such a Council. The first Inter-State Council was established by a Presidential Order in 1990 based on the recommendations of the Sarkaria Commission.
Step 2: Evaluating Reason (R).
Reason (R) is also correct. Article 263 explicitly defines the duties of the Council, which include: (a) inquiring into and advising upon disputes which may have arisen between States; (b) investigating and discussing subjects in which some or all of the States, or the Union and one or more of the States, have a common interest; and (c) making recommendations upon any such subject.
Step 3: Analyzing the Relationship.
While both statements are factually accurate, the Reason (R) is a description of the Council's functions, not the reason why the President has the power to establish it. The President establishes the Council because the Constitution grants that power for the purpose of "public interest" and coordination, not solely because the Council has an advisory role in disputes. Therefore, (R) is not the logical explanation for (A).