The accumulation of several contiguous properties under one ownership, thus creating a large parcel of proportionate greater value, involves:

depreciation
plottage
corner influence
zoning value
plottage

Plottage

Explanation:

Plottage is a value increase achieved by the amalgamation of conterminous or contiguous land into one piece under one ownership. The effect of such  combination is that it produces a value that will be much greater than the sum of the value of the individual land.

The very process involved in the combination is referred to as assemblage. sometimes the word assemblage is used loosely to mean plottage.

answer; (b) insider trading;