Step 1: Understanding the question.
The question asks about the uneven economic development across regions in India, which depends on the regional conditions.
Step 2: Analyzing the statements.
(I) Policies for economic development are centrally planned: This statement explains the structure of the policies but does not directly address the regional disparities in economic development.
(II) Conditions in India vary from one region to another: This statement directly addresses the cause of uneven development, as differing regional conditions can lead to varying levels of economic development.
Step 3: Conclusion.
The correct answer is (B) If only statement II is required to answer the question, as it directly explains why economic development is not uniform across regions.