The passage mentions that the main issue with water availability in India is the disparity between the abundance of water during the monsoon (June to September) and the scarcity in the remaining months. To address this imbalance, a practical, rational, and lasting solution would involve buffer stocking of water — this can be achieved by building dams to store excess water during the monsoon and recharging aquifers to ensure water availability during the dry months. This solution aims to regulate water consumption throughout the year and manage the skewed availability of water in a sustainable way.

The other options, like constructing concrete storage tanks, changing cropping patterns, or interlinking rivers, do not directly address the long-term management of water or may not provide a sustainable solution.

Thus, the correct answer is D, Buffer stocking of water through dams and recharging aquifers.