The correct answer is (b).
The Nomadic Elephant is a joint military exercise between India and Mongolia. It is held annually and is aimed at improving the interoperability between the two armies. The exercise is conducted in different parts of India and Mongolia. The first edition of the exercise was held in 2017 in Mongolia. The second edition was held in 2018 in India. The third edition was held in 2019 in Mongolia. The fourth edition was held in 2020 in India. The fifth edition was held in 2021 in Mongolia.
The exercise includes a wide range of activities such as joint training, joint exercises, and joint operations. The exercise is aimed at improving the interoperability between the two armies and to develop a joint understanding of the operational environment. The exercise also helps to build trust and cooperation between the two armies.
The exercise is a significant step in the development of the bilateral relations between India and Mongolia. The exercise helps to strengthen the strategic partnership between the two countries. The exercise also helps to promote peace and stability in the region.
The other options are incorrect because they are not the countries with which India conducts the Nomadic Elephant exercise.