Pants and Skirt Corporations Are Affiliated and Have Filed Consolidated

Pants and Skirt Corporations are affiliated and have filed consolidated tax returns for the past three years. Pants acquires 100% of Zipper stock on January 1 of 2019. Zipper Corporation filed separate returns previously. Pants, Skirt, and Zipper filed a consolidated return for 2019 and reported the following taxable incomes: $\begin{array}{|c|c|r|}\hline\text { Corporation } & \text { Taxable Income } & \text { Taxable Income } \\& 2018 & 2019\\\hline \text { Pants } & \$ 18,000 & \$ 12,000 \\\text { Skirt } & 9,000 & 8,000 \\\text { Zipper } & (17,000) & 20,000 \\\hline\end{array}$ How much of the 2018 Zipper NOL be used to offset CTI in 2019?

A) $0
B) $17,000
C) $20,000
D) $16,000