Final answer:
Standards are considered an external source of knowledge as they are established by external entities and provide a reference for various practices. This category includes industry practices, quality measures, and legal standards. They differ from personal lessons learned, intellectual property, or process improvements which are internal knowledge sources.
Step-by-step explanation:
An external source of knowledge refers to information or insights obtained from outside an individual's personal experience. Examples of external sources of knowledge include books, research articles, educational materials, standards, and testimonies from others. In the context of the student's question, option d. Standards are typically considered an external source of knowledge because they are established by organizations or committees and provide a reference point that is outside of one's personal lessons learned or intellectual property. These standards could pertain to industry practices, quality measures, legal requirements, and more.
Scientific knowledge often builds upon the findings of others and is shared through publications and testimonies.Scientists use previous studies and data to inform their own research and contribute new insights to the field. Likewise, international law also relies on external sources such as treaties and international agreements, which are essential references for legal practices across countries.