Motor Vehicles account has a balance of $80,000 and provision for depreciation account has a balance of $20,000. One motor vehicle which was bought two years ago for $10,000 for $20.000, The motor vehice has been depreciated at 20% per annum on cost. What was the balance on the provision of depreciation after this disposal?

a. $12,000.

b. $15,600.

c. $16,000.

d. $10,400.