Which two main types of GIS data sources are identified?

The correct identification of the two main types of GIS data sources is primary data and secondary data. Primary data refers to information collected firsthand for a specific purpose or project. This data is typically gathered through direct methods such as surveys, remote sensing, and field observations. It is considered highly accurate and relevant because it is tailored to the specific needs of the GIS analysis.

On the other hand, secondary data consists of information that has already been collected, processed, and published by someone else. This may include government reports, published maps, and previously gathered datasets from various sources. While secondary data is generally more accessible and cost-effective to obtain, it may not always match the specific requirements or current conditions pertinent to the GIS project's objectives.

The other choices do not represent the main distinctions in GIS data sources. Experimental data, field data, administrative data, qualitative data, and quantitative data describe various facets or classifications within the realm of data but do not encapsulate the primary and secondary data framework, which is foundational for understanding GIS data sources.