TNM Inc Uses LIFO and Was Founded in on January 1

Multiple Choice

TNM Inc. uses LIFO and was founded in on January 1, 2017. At the end of 2017, TNM disclosed that the LIFO reserve was $1 million, indicating that the ending inventory balance would have been $1 million higher under FIFO. At the end of 2018, the LIFO reserve decreased to $0.5 million and inventory balances were relatively stable compared to 2017. Which of the following is true regarding TNM's costs?

A) Costs have been increasing since TNM was founded because the LIFO reserve is greater than zero.
B) Costs have been decreasing since TNM was founded because the LIFO reserve is greater than zero.
C) Costs were increasing in 2018, but decreasing in 2017.
D) Costs were decreasing in 2018, but increasing in 2017.