Concept:
Botanical names are scientific names assigned to plants using binomial nomenclature. Each plant has a unique Latin name consisting of genus and species.
Step 1: Understanding botanical names.
Botanical names help in universal identification of plants irrespective of regional languages.
Step 2: Identifying the guava plant.
The guava plant belongs to the genus \textit{Psidium} and species \textit{guajava}.
Step 3: Evaluating the options.
- Mangifera indica $\rightarrow$ Botanical name of mango (incorrect)
- Psidium guajava $\rightarrow$ Botanical name of guava (correct)
- Musa paradisiaca $\rightarrow$ Botanical name of banana (incorrect)
- Citrus sinensis $\rightarrow$ Botanical name of orange (incorrect)
Step 4: Additional insight.
Guava is a tropical fruit rich in vitamin C and dietary fiber. It is widely cultivated in India and is known for its medicinal and nutritional value.
Step 5: Conclusion.
Thus, the botanical name of guava is \textit{Psidium guajava}.