The correct answer is option 2, which states that the Union Parliament can re-organize or alter the boundaries of the States of the Indian Union by a simple majority in the ordinary process of legislation.

Let`s analyze the other options:

Option 1 suggests that the Union Government can re-organize or alter State boundaries with the consent of the concerned State Government. While the Union Government does play a role in this process, the ultimate authority lies with the Union Parliament.

Option 3 states that a two-thirds majority of both Houses of Parliament is required for re-organization or alteration of State boundaries. This is not accurate as a simple majority is sufficient.

Option 4 proposes that a two-thirds majority of both Houses of Parliament and the consent of the concerned State Legislatures is necessary. However, the consent of the State Legislatures is not required, as the Union Parliament has the power to make changes to State boundaries without their consent.

In conclusion, option 2 is correct because the Union Parliament can re-organize or alter State boundaries with a simple majority in the ordinary legislative process.