Which of the following cultural festivals is natively celebrated in the Union Territory of Ladakh?

The correct option is Hemis Festival.

Step-by-step breakdown:
1. Hemis Festival: The Hemis Festival is a famous cultural and spiritual festival natively celebrated in the Union Territory of Ladakh. It takes place annually at the historic Hemis Monastery (Hemis Gompa) in Leh. The festival marks the birth anniversary of Lord Padmasambhava (Guru Rinpoche), who is revered for introducing Tantric Buddhism to Tibet and the Himalayan region. A major feature of this grand festival is the sacred mask dance performance known as Cham, performed by monks to traditional music played on cymbals, drums, and trumpets.
2. Bhogali Bihu: Also known as Magh Bihu, this is a major harvest festival celebrated natively in the state of Assam.
3. Teej: This festival is primarily celebrated by women across Northern and Western India (such as Rajasthan, Haryana, and Uttar Pradesh) to welcome the monsoon season and dedicate prayers to Goddess Parvati and Lord Shiva.
4. Bonalu: This traditional Hindu festival dedicated to Goddess Mahakali is celebrated natively in the state of Telangana, particularly in the twin cities of Hyderabad and Secunderabad.

Therefore, among the given choices, the cultural festival natively celebrated in Ladakh is the Hemis Festival.