The correct answer is option 'D' - Mongolian Plateau.

The Mongolian Plateau is a vast elevated region located in East Asia, covering parts of Mongolia, China, and Russia. It is surrounded by several mountain ranges, including the Greater Hinggan Mountains in the east, the Yin Mountains to the south, the Altai Mountains to the west, and the Sayan and Khentii mountains to the north.

Let's break down the surrounding mountain ranges and their locations in more detail:

1. Greater Hinggan Mountains:
- Located in northeastern China, the Greater Hinggan Mountains form the eastern boundary of the Mongolian Plateau.
- They stretch from the Russian Far East in the north to northeastern China in the south.
- These mountains are known for their dense forests and rugged terrain.

2. Yin Mountains:
- Also known as the Da Hinggan Ling, the Yin Mountains are situated in northern China.
- They run parallel to the Greater Hinggan Mountains and form the southern border of the Mongolian Plateau.
- The Yin Mountains are an important water source for the region, with numerous rivers originating from their slopes.

3. Altai Mountains:
- The Altai Mountains are a vast mountain range located in Central Asia, spanning parts of Mongolia, China, Russia, and Kazakhstan.
- They form the western boundary of the Mongolian Plateau.
- The Altai Mountains are known for their rugged peaks, glaciers, and diverse flora and fauna.

4. Sayan and Khentii Mountains:
- The Sayan Mountains are situated in southern Siberia, Russia, while the Khentii Mountains are located in northeastern Mongolia.
- These two mountain ranges form the northern border of the Mongolian Plateau.
- The Sayan Mountains are characterized by alpine meadows, deep valleys, and numerous lakes, while the Khentii Mountains are known for their forests and grasslands.

In conclusion, the Mongolian Plateau is surrounded by the Greater Hinggan Mountains in the east, the Yin Mountains to the south, the Altai Mountains to the west, and the Sayan and Khentii mountains to the north. This geographical location gives the plateau its unique characteristics and influences its climate, vegetation, and wildlife.