By what right could a county acquire private land necessary to build a new highway...

Eminent domain is the government's right to take private property for public use, with just compensation to the owner. The legal process used to exercise this right is called condemnation. Therefore, while condemnation is the procedure, the actual right exercised is eminent domain. Escheat involves reverting property to the state when there is no heir, and police power involves regulations like zoning. Correct answer: B.

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