Sort the Constitution into three drawers before touching the options. Drawer one holds the provisions that can be changed by an ordinary Bill with a simple majority. Drawer two holds the bulk of the Constitution, needing a special majority under Article 368, meaning a majority of the total membership of each House plus two thirds of those present and voting. Drawer three holds the federal core, needing that special majority plus ratification by at least half the State legislatures. Then ask which option sits in drawer one.
So option (B) is the answer. The design point behind it is worth noting. The framers deliberately made the map of India easy to redraw, so that the Union could reorganise States as needs changed, which is why India is often described as an indestructible union of destructible States.
Let's summarize:
A change in the name and boundaries of States needs only a simple majority, so option (B) is correct.