The correct answer is 3R8C. The National Education Plan aims to improve the quality of education in Thailand by focusing on three main areas: access, quality, and relevance. The "3R8C" stands for the eight key strategies of the plan, which include reforming the curriculum, enhancing teacher quality, promoting research and innovation, and strengthening the management system. Therefore, the outcome of the National Education Plan is expected to be achieved through the implementation of these strategies outlined in 3R8C.