Step 1: Define Quaternary activities. The quaternary sector of the economy is the knowledge-based part, which generally includes services such as information technology, information-generation and -sharing, media, and research and development, as well as knowledge-based services like consultation, education, and financial planning.
Step 2: Classify the given activities.
(A) Manufacturing computer, (B) Printing books, and (C) Paper and pulp production are all forms of manufacturing. They involve taking raw or processed materials and creating a physical product. These are secondary activities.
(D) A University teacher is involved in the creation, organization, and dissemination of specialized knowledge. This fits perfectly within the definition of the quaternary sector.