Final answer:
A historical geographer would be the most useful for Khalid to study in order to understand how the towns and cities in his region are interconnected.
Step-by-step explanation:
The historical geographer would be the most useful for Khalid to study in order to understand how the towns and cities in his region are interconnected. Historical geographers study the spatial distribution of human settlements and the causes and consequences of human settlement and distribution over the landscape. They examine the past patterns and processes of urban development and can provide insights into the historical factors that have shaped the interconnections between towns and cities. By analyzing maps, archival records, and historical documents, historical geographers can uncover how towns and cities have evolved and influenced each other throughout history.