Explanation:

- Separation Convention of 1924:

- This is the correct answer.

- It refers to the decision made in 1924 to separate the Railway Budget from the General Budget in India.

- The rationale was to provide focused attention and specialized consideration for the railway sector.

- Distributive Convention of 1925:

- There's no historical reference to this convention concerning the separation of budgets.

- Likely a distractor option.

- Bifurcation of Estimates of 1924:

- Relates to the process of dividing estimates but is not directly the reason for separating the budgets.

- It sounds relevant but isn’t the correct historical reference.

- Equalising Convention of 1925:

- This option doesn't relate to the budget separation.

- Possibly meant to create confusion.

Your answer is RIGHT.