WaterCo, a U.S. corporation, purchases inventory for resale from unrelated distributors outside the U.S. It resells this inventory to U.S. customers with title passing inside the United States. What is the sourcing of WaterCo's inventory sales income?

a.50% U.S. source and 50% foreign source.

b.100% foreign source.

c.50% foreign source and 50% sourced based on location of manufacturing assets.

d.100% U.S. source.