Sargent Corporation bought equipment on January 1, 2020. The equipment purchase cost $540,000, Transit insurance $20,000, annual maintenance $30,000 and had an expected residual value of $90,000. The life of the equipment was estimated to be 6 years. The depreciatable cost of the equipment is: A. $540,000 B. $450,000. C. $500,000. D. $470,000