A taxpayer owns 40 shares of Corporation A and is a 20% partner of a partnership that also owns 40 shares of the corporation. The other 80% of the partnership is owned by the taxpayer's neighbors, who are unrelated to the taxpayer. How many shares of Corporation A does the taxpayer treat as owning directly and indirectly through the partnership?

A. 40

B. 48

C. 72

D. 80