For a galvanic cell that uses the following two half-reactions, Cr2O72-(aq) + 14 H+(aq) + 6 e- → 2 Cr3+(aq) + 7 H2O(l) Pb(s) → Pb2+(aq) + 2 ehow many moles of Pb(s) are oxidized by three mol es of Cr2O72-?

A) 3

B) 6

C) 9

D) 18