McSweeney agrees to clear out Brown's basement but no price is set at the time.Brown argues, once McSweeney has done the work, that since no price was agreed upon he will not pay the excessive bill.What principle of law will the courts use to determine how much Brown should have to pay?

a.Undue Influence

b.Rectification

c.Quantum Meruit

d.Force Majeure

e.Frustration