Parcels A, B, and C are located side by side and owned by three different owners. A is worth $20,000, B is worth $27,000, and C is worth $16,000 for a total of $63,000. A developer believes that if all three can be purchased, the larger parcel would be worth $85,000. By assembling these under one owner they would be worth $22,000 more than their individual values. This demonstrates which principle of value?
a) Contribution
b) Substitution
c) Plottage
d) Regression