Concept: The question tests on basics of Percentage
Solution:
Let the price / kg = 100
Expenditure = Price * Quantity (consumption)
Old expenditure = 100 * 25 = 2500
New Price = 30% Increase = 100 * 1.3
New Expenditure = 30% increase = 2500 * 1.3
Therefore 2500 * 1.3 = 100 * 1.3 * Quantity (New)
Q = 25 kg
Option B