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. The delay pushed the harvest dangerously close to the winter frost.
B. Agricultural scientists now recommend shifting to shorter-duration crop varieties.
C. The monsoon arrived late for the fourth consecutive year.
D. Farmers in the region had already delayed sowing by three weeks.