Step 1: Understanding the Concept:
Economic activities are divided into sectors. Quaternary activities are a specialized part of the service sector that focuses on the "knowledge economy."
Step 2: Detailed Explanation:
1. Option A and B: Teaching and BPO services are classified under Tertiary activities, which involve providing general services to the public or businesses.
2. Option D: Operating machinery is a Secondary activity related to manufacturing and production.
3. Option C: Quaternary activities involve the collection, production, and dissemination of information, as well as high-end research and software development. These activities require high professional and technical skills.
Step 3: Final Answer:
Since Software Development and Information Research are knowledge-centric and involve high-level information processing, they are quaternary activities. Thus, (C) is the correct answer.