Which of the following National Parks of India have been declared UNESCO World Heritage Sites? 1. Keoladeo National Park 2. Sundarbans National Park 3. Kaziranga National Park 4. Ranthambore National Park – select the correct combination using the code given below.

Introduction / Context:
UNESCO World Heritage Sites are locations of outstanding cultural or natural value. In India, several National Parks have received this status for their biodiversity, unique ecosystems and conservation importance. This question examines whether candidates know exactly which parks among the four listed are recognised as UNESCO World Heritage Sites, which is a frequent topic in competitive examinations.

Given Data / Assumptions:

• Four Indian National Parks are listed: Keoladeo, Sundarbans, Kaziranga and Ranthambore.
• The task is to identify which of them are UNESCO World Heritage Sites.
• Answer choices are given in terms of combinations of park numbers.
• We rely on the standard UNESCO list of natural World Heritage Sites in India.

Concept / Approach:
The key idea is to match each park with UNESCO World Heritage status. Keoladeo National Park in Rajasthan is inscribed as a World Heritage Site for its wetland bird habitat. Sundarbans National Park in West Bengal is listed for its mangrove forest and tiger habitat. Kaziranga National Park in Assam is recognised for its population of one horned rhinoceros and rich biodiversity. Ranthambore National Park, although a famous tiger reserve, has not been accorded UNESCO World Heritage Site status as a National Park.

Step-by-Step Solution:
Step 1: Confirm that Keoladeo National Park (formerly Bharatpur Bird Sanctuary) is a UNESCO World Heritage Site classified under natural criteria.Step 2: Recall that Sundarbans National Park, forming part of the world's largest mangrove forest, is inscribed as a World Heritage Site.Step 3: Remember that Kaziranga National Park, famous for the one horned rhinoceros, is also in the UNESCO World Heritage list.Step 4: Note that Ranthambore National Park, despite its prominence for tiger conservation and tourism, is not declared a UNESCO World Heritage Site.Step 5: Combine these facts: parks 1, 2 and 3 are World Heritage Sites, while 4 is not, corresponding to option “1, 2 and 3 only”.

Verification / Alternative check:
Another way to verify is to quickly recall the standard list of Indian natural World Heritage Sites, which includes Keoladeo, Sundarbans, Kaziranga, Nanda Devi and Valley of Flowers, Great Himalayan National Park and others. Ranthambore does not appear on this list. This cross check eliminates doubt and confirms that only the first three parks from the question have UNESCO status.

Why Other Options Are Wrong:
1 and 2 only: Incorrect because Kaziranga National Park is also a World Heritage Site and must be included.
3 and 4 only: Wrong because Keoladeo and Sundarbans are also in the UNESCO list, and Ranthambore is not.
1, 2, 3 and 4: Incorrect because it wrongly assumes that Ranthambore National Park is also a UNESCO World Heritage Site.

Common Pitfalls:
Many candidates over generalise and think that every famous tiger reserve must be a World Heritage Site, leading them to wrongly include Ranthambore. Others may forget Keoladeo because it is relatively small compared to other parks. To avoid errors, it is useful to memorise the exact list of Indian World Heritage National Parks rather than relying only on perceived fame or tourism popularity.

Final Answer:
The UNESCO World Heritage Sites among the listed parks are 1. Keoladeo, 2. Sundarbans and 3. Kaziranga National Parks, that is, option “1, 2 and 3 only”.