Answer : 2. "Hyper Arid Partial irrigated zone"
Explanation :

Rajasthan's agriculture is divided into 10 parts based on crop climate zone.

1. In terms of area, the largest agro-climatic zone of Rajasthan is I-C (extremely dry partially irrigated zone).

2. Rajasthan's smallest agricultural crop in terms of area is climate zone IV-B.

3. On the basis of agricultural area, the largest agricultural crop in Rajasthan is climate zone III-B.

4. The least cultivated climate zone of Rajasthan is IV-A.

5. Swami Kesavanand Rajasthan Agricultural University is in I-C block.

6. Maharana Pratap University of Agriculture and Technology, Udaipur is in IV-A block.