The Siroi Hills in Manipur are known for their:

Shirui Lily
Waterfalls
Tea plantations
Cave systems

The correct answer is: Shirui Lily.

The Shirui Lily is a rare and endangered species of lily that is found only in the mountains of Manipur. It is a beautiful flower that blooms in the spring and is a symbol of the state of Manipur. The Shirui Lily is also known as the “Queen of the Lily” and is considered to be one of the most beautiful flowers in the world.

The other options are incorrect because:

  • Waterfalls: There are many beautiful waterfalls in the Siroi Hills, but they are not the main reason why the hills are famous.
  • Tea plantations: There are some tea plantations in the Siroi Hills, but they are not as famous as the tea plantations in other parts of India.
  • Cave systems: There are some cave systems in the Siroi Hills, but they are not as well-known as the cave systems in other parts of India.