Final answer:
The ArcGIS Block Statistics geoprocessing tool requires the Spatial Analyst extension, which provides the necessary functionality for advanced spatial data analysis and is ideal for calculating the mean slope per watershed.
Step-by-step explanation:
An ArcGIS user working on calculating the mean slope for each watershed using the Block Statistics geoprocessing tool needs to have the correct extension enabled to perform their analysis. Considering the necessities of the task, the applicable extension would be the Spatial Analyst extension. Tools within this extension are crafted to handle the complexities of spatial data and leverage statistical computations that are inherently geographical. The Spatial Analyst extension encompasses a variety of tools for carrying out advanced spatial data analysis, such as measuring topographic patterns, analyzing surfaces, and working with raster data, which is ideal for tasks like estimating the mean slope per watershed.
It is important to recognize that GIS specialists employ these tools across various sectors, from government to business, to derive insightful geographical information that can influence pivotal decisions. The practice of spatial analysis, a subfield of geography, asserts its significance by providing geographers with means to visualize and understand the distribution, patterns, and trends within spatial data, vital for making informed strategic decisions.
The correct option to enable the use of the Block Statistics geoprocessing tool in ArcGIS is option B, the Spatial Analyst extension.