Alex purchased a rental house 4 years ago for $270,000. Her depreciation at the time of the sale is $40,000. Due to a decrease in real estate prices, she sells the house for only $240,000 in 2020. What is her gain or loss for tax purposes?
a. $0
b. $10,000 loss
c. $10,000 gain
d. $35,000 loss
e. $25,000 gain