The correct answer is option D, Jammu and Kashmir. Here is an explanation of why Jammu and Kashmir shares its borders with Pakistan, China, Nepal, and Bhutan:

1. Pakistan: Jammu and Kashmir shares a long border with Pakistan. The Line of Control (LoC) separates the Indian-administered Jammu and Kashmir from Pakistan-administered Azad Kashmir. The LoC is approximately 740 kilometers long and serves as the de facto border between the two countries.

2. China: Jammu and Kashmir shares a border with China's Xinjiang and Tibet regions. This border is known as the Line of Actual Control (LAC) and runs through the eastern part of the region. The LAC is about 1,126 kilometers long and is a contentious border with occasional border disputes between India and China.

3. Nepal: Jammu and Kashmir does not directly share a physical border with Nepal. However, it is in close proximity to Nepal, and there are certain regions in Jammu and Kashmir that are located near the Nepal border. For example, areas like Ladakh and Uttarakhand, which are part of Jammu and Kashmir, share a border with Nepal.

4. Bhutan: Similar to Nepal, Jammu and Kashmir does not directly share a physical border with Bhutan. However, it is in close proximity to Bhutan, and there are certain regions in Jammu and Kashmir that are located near the Bhutan border. For instance, the Indian state of Sikkim, which is located in the eastern part of Jammu and Kashmir, shares a border with Bhutan.

In summary, Jammu and Kashmir shares its borders with Pakistan, China, Nepal (indirectly), and Bhutan (indirectly). The borders with Pakistan and China are well-defined and have been the subject of territorial disputes, while the proximity to Nepal and Bhutan allows for cultural and economic exchanges between the regions.