The correct options are
A Abundant rainfall
C Moderately thick layers of alluvial soil in the river basins
E Laterite soil along the hilly tracts.
The midland in Kerala is characterised by the most diverse crops. Cereals, vegetables, tuber crops, etc.Abundant rainfall, moderately thick layers of alluvial soil in the river basins, and laterite soil along the hilly tracts are the favourable geographical factors for the crop diversity in the midland region.