The correct option is "Both I and II" because the Rashtriya Gokul Mission aims to enhance the productivity of indigenous cattle and buffalo breeds, which are often owned by small and marginal farmers and landless laborers, thus directly contributing to the upliftment of the rural poor. Additionally, the mission promotes sustainable and scientific methods for the rearing and conservation of these breeds, ensuring not only economic benefits for farmers but also the preservation of genetic diversity and traditional livestock breeding practices, which are critical for rural sustainability and food security. This aligns with broader agricultural and rural development goals central to India's policy framework.