Which organization focuses specifically on providing guidelines and standards for GIS practice?

The organization that focuses specifically on providing guidelines and standards for GIS practice is the Geographic Information Systems Certified International (GISCI). GISCI is known for its development of the GIS Certification Institute's standards and guidelines for GIS professionals, which emphasize ethical practices in GIS, promote education, and ensure a high level of proficiency in GIS technologies.

While the other organizations also play essential roles in the GIS community, their focuses differ. For instance, the Open Geospatial Consortium (OGC) primarily advocates for interoperability standards in geospatial and location-based services, which ensures that various GIS technologies can work together effectively. The National States Geographic Information Council (NSGIC) works on policy development and state-level geographic information issues, promoting the use of geospatial data for public benefit. The Urban and Regional Information Systems Association (URISA) emphasizes professional education and networking for GIS professionals, focusing on urban planning and local government issues.

Thus, GISCI specifically dedicates itself to establishing guidelines and standards critical for the practice of GIS, making it the correct answer in this context.