- Based on the Budget Estimates (BE) for 2013-14 for the Union Government's gross tax revenue from the specified sources: - Corporation Tax: ₹ 3,79,600 crore - Customs: ₹ 1,83,000 crore - Union Excise Duties: ₹ 1,90,000 crore - Service Tax: ₹ 1,87,000 crore - Arranging these in ascending order (smallest to largest): - Customs (₹ 1,83,000 cr) - Source 2 - Service Tax (₹ 1,87,000 cr) - Source 4 - Union Excise Duties (₹ 1,90,000 cr) - Source 3 - Corporation Tax (₹ 3,79,600 cr) - Source 1 - The ascending order is 2-4-3-1. - However, the provided options do not include 2-4-3-1. Option D is 4-3-2-1, which implies Service Tax