Concept:
Improved fruit varieties are developed for traits like dwarfness, early bearing, and suitability for high-density planting.
Step 1: Understanding "Pusa Nanha".
Pusa Nanha is a well-known dwarf variety developed for compact growth.
Step 2: Identifying the crop.
It is a variety of papaya characterized by short stature and early fruiting.
Step 3: Key features.
- Dwarf and compact plant
- Suitable for kitchen gardens and pot culture
- Early bearing
Step 4: Evaluating the options.
- Papaya $\rightarrow$ Correct
- Mango $\rightarrow$ Not correct
- Banana $\rightarrow$ Not correct
- Guava $\rightarrow$ Not correct
Step 5: Additional insight.
Being dioecious, papaya plants have separate male and female plants, which is important for pollination and fruit production.
Step 6: Conclusion.
Thus, Pusa Nanha is a dwarf variety of papaya.