An urban agglomeration may consist of which of the following?

Majority of metropolitan and mega cities are urban agglomerations. An urban agglomeration may consist of any one of the following three combinations: (i) a town and its adjoining urban outgrowths, (ii) two or more contiguous towns with or without their outgrowths, and (iii) a city and one or more adjoining towns with their outgrowths together forming a contiguous spread.