Quaternary activities focus on the generation, dissemination, and application of information and knowledge, particularly related to research and development. These activities are centered around intellectual efforts that involve specialized knowledge and technical skills. While statement ii refers to the production of tools, which is more related to secondary activities like manufacturing, it does not align with the core characteristics of quaternary activities. Hence, the correct answer is (C), as statements i, iii, and iv correctly describe the nature of quaternary activities.