The four sentences labelled A, B, C and D, given below in jumbled order, together form a coherent paragraph. Arrange the sentences in the most logical order and choose the sequence that produces the best paragraph.

A. A group of them began collecting and cataloguing the hardy local varieties their grandparents had once sown.
B. Agricultural universities, initially dismissive of the effort, now send researchers to study how these varieties survive on residual moisture.
C. Three consecutive crop failures pushed the farmers of a dryland belt in Karnataka to question their dependence on purchased hybrid seed.
D. The collection grew into a community seed bank that lends seed to any member against a promise to return double the quantity after harvest.