Fisher Company purchased a patent on January 1, 2015 for P428,400. The patent was being amortized over its legal of 15 years expiring on January 1, 2030. On January 1, 2018, Fisher determined that the economic life of the patent would not last longer than 10 years from the date of acquisition. What amount should be reported in the balance sheet as patent, net of accumulated amortization on December 31, 2020?

a. P314,160

b. P302,400

c. P244,800

d. P195,840

Please include a step-by-step explanation and solution.