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