Answer: (Detailed Solution Below)
Option C: A is true but R is false
Detailed Solution:
The correct answer is “A is true but R is false”.
Black soils, often referred to as Regur or Black Cotton soils, are predominant in the Deccan Trap region.
While black soils (Regur soils) are rich in minerals and have good moisture-retention properties, they are not particularly known for being rich in humus. Humus is more associated with organic content, and these soils are more noted for their mineral content rather than organic.
The primary reason for the black color of these soils is the presence of iron and other minerals.