Original jurisdiction of the Supreme Court comes under which article?

Answer: Option A

The correct answer is A: Article 131.
Let's break down why:
Original Jurisdiction means the Supreme Court is the first court to hear a case.
This is different from appellate jurisdiction, where the Supreme Court hears cases that have already been decided by lower courts.
Article 131 specifically deals with the Supreme Court's original jurisdiction, especially in disputes between the Government of India and one or more states, or between states themselves.
Article 124 deals with the establishment and constitution of the Supreme Court.
Article 280 is about the Finance Commission, which deals with financial relations between the Union and the States.
Article 290 deals with adjustment in respect of certain expenses and pensions.
Therefore, only Article 131 directly addresses the Supreme Court's power to hear certain cases first.