Step 1: Understanding the Question:
The question asks to identify the fruit crop for which "Pusa Nanha" is a known variety. The description includes key traits: dioecious and dwarf.
Step 2: Key Formula or Approach:
This is a factual question about crop varieties. The name "Pusa Nanha" itself provides clues. "Pusa" indicates it was developed at the IARI in Pusa, New Delhi, and "Nanha" means "small" or "dwarf" in Hindi. The term "dioecious" means that male and female flowers are on separate plants.
Step 3: Detailed Explanation:
(A) Papaya (Carica papaya): "Pusa Nanha" is a very famous and revolutionary dwarf variety of papaya. Its short stature allows for high-density planting and makes it suitable for growing in pots and home gardens. Papaya plants are naturally dioecious (though many modern varieties are gynodioecious or hermaphrodite), fitting the description.
The other fruits do not fit the description:
(B) Mango: 'Amrapali' is a dwarf mango, but not 'Pusa Nanha'.
(C) Banana: Banana varieties are not referred to as dioecious.
(D) Guava: Dwarf guava varieties exist, but 'Pusa Nanha' is not one of them.
Step 4: Final Answer:
"Pusa Nanha" is a well-known dwarf, dioecious variety of Papaya. Therefore, option (A) is correct.