The ranking of settlements into rural and urban is mostly based on

Step 1: Analyze the question The question asks what criterion is mostly used to classify settlements as rural or urban.

Step 2: The concept Settlements are classified in several ways:

• Pattern (nucleated, linear, dispersed) describes the arrangement or layout of buildings, not whether a place is rural or urban.
• Location (coastal, riverine, hilltop) describes where a settlement is sited, not its rank.
• Size refers to the physical area covered, which is a loose indicator and can be misleading.
• Population is the number of people living there. This is the main criterion used to separate rural from urban settlements. In Nigeria, for example, a settlement with about 20,000 or more inhabitants is typically classed as urban, while smaller ones are rural. Other criteria, such as functions and services, are also used, but population is the most common.

Step 3: Work through the options

• A. Location: it does not determine rank. ❌
• B. Size: this is related, but it is vague. Size of area does not reliably show whether a place is urban. ❌
• C. Pattern: it describes shape or layout only. ❌
• D. Population: it is the standard, measurable basis for ranking. ✔️

Step 4: Answer The correct option is D. population.

Exam tip: When you see "rural vs urban" in Geography, think "number of people" first, then functions and amenities. Remember Pattern = Shape, Location = Site, Population = Count.