Answer : 3. "गोगाजी "
Explanation :

1. The state tree of Rajasthan is Khejri. This tree is found in about two-thirds of the total geographical area of the state and has great importance culturally and economically.

2. The scientific name of Khejri is Prosopis cinerea. It is a drought-tolerant tree that can survive even in areas with low rainfall. This tree is found in desert areas and is found in abundance in the Thar Desert of Rajasthan.

3. Khejri tree is considered the symbol of Gogaji folk deity in Rajasthan.