राजस्थान के निम्नलिखित में से किस जिले में मुख्य रूप से भूरी मिट्टी (Brown soils) पाई जाती है?

'Mixed Red and Black' soil in Rajasthan is mainly found in which district combination?

Assertion (A): The 'Vertisols' soil type is predominant in the Hadoti region of Rajasthan. Reason (R): This region is characterized by volcanic basaltic lava that weathers into black cotton soil.