A Building with a Cost of $500 000,an Estimated Residual

A building with a cost of $500 000,an estimated residual value of $50 000,and an estimated useful life of 20 years was depreciated by the straight-line method for 10 years.In the eleventh year,it was determined that the useful life should be extended by 10 years (i.e.from 20 years to 30 years) .The residual value was to remain the same.The depreciation expense for the eleventh year is:

A) $11 250.
B) $12 500.
C) $13 750.
D) $15 000.