In 2021, Tuna Industries changed from the double-declining balance method to the straight-line method for all its plant assets. There were no changes to salvage values or useful lives for any of the assets. Plant assets, acquired on January 2, 2018, had an original cost of $4,000,000 with a $200,000 salvage value and a 10 year estimated useful life. Depreciation expense amounts calculated under the double-declining balance method for years 2018 through 2021 are as follows:

2018 $800,000

2019 $640,000

2020 $512,000

2021 $409,600

What amount should Tuna record for depreciation expense in 2021?

a. $155,500

b. $184,800

c. $264,000

d. $380,000