The festival of Shivratri is celebrated with great fervor in:

Jammu region
Ladakh
Gilgit-Baltistan
Kashmir Valley

The correct answer is: d) Kashmir Valley.

Shivratri is a Hindu festival that celebrates the union of the god Shiva and his consort Parvati. It is observed on the 14th night of the dark half of the month of Phalguna (February–March) in the Hindu calendar. The festival is marked by fasting, prayer, and the performance of rituals.

In Kashmir Valley, Shivratri is a major festival that is celebrated with great fervor. The festival is marked by a number of religious and cultural events, including processions, fairs, and music and dance performances. The main attraction of the festival is the nightlong vigil at the temples of Shiva, which are decorated with flowers and lights.

The other options are incorrect because:

  • Jammu region is a region in the Indian state of Jammu and Kashmir. It is home to a number of Hindu temples, but Shivratri is not as widely celebrated there as it is in Kashmir Valley.
  • Ladakh is a region in the Indian state of Jammu and Kashmir. It is a predominantly Buddhist region, and Shivratri is not as widely celebrated there as it is in other parts of the state.
  • Gilgit-Baltistan is a region in the northern part of Pakistan. It is a predominantly Muslim region, and Shivratri is not as widely celebrated there as it is in other parts of the country.