**Explanation:**

The correct answer is 'A) Sri Lankan Tamils.'

**Sri Lankan Tamils:**
- Tamil natives of Sri Lanka are referred to as Sri Lankan Tamils.
- They are a distinct ethnic group in Sri Lanka and are predominantly Tamil-speaking.
- They have a long history in the country, and their presence can be traced back to ancient times.
- Sri Lankan Tamils are considered one of the major ethnic groups in Sri Lanka, alongside Sinhalese, Sri Lankan Moors, and Indian Tamils.

**Indian Tamils:**
- Indian Tamils, also known as Hill Country Tamils or Upcountry Tamils, are descendants of Tamil laborers brought to Sri Lanka during the British colonial period.
- They were brought to the country to work on tea plantations in the central highlands.
- Indian Tamils are considered a separate ethnic group from Sri Lankan Tamils due to their distinct historical background and cultural practices.

**Muslim Tamils:**
- The term "Muslim Tamils" is not commonly used to refer to a specific ethnic group in Sri Lanka.
- Sri Lankan Muslims, also known as Moors, are an ethnic minority in the country who primarily practice Islam.
- While there are Tamil-speaking Muslims in Sri Lanka, they are not specifically referred to as "Muslim Tamils."

**Conclusion:**
- Tamil natives of Sri Lanka are called Sri Lankan Tamils, as they are a distinct ethnic group with a long history in the country.
- Other terms such as Indian Tamils and Muslim Tamils refer to different ethnic groups within the larger Tamil community in Sri Lanka.

Sri Lankan Tamils is the correct answer
but is to be explained here

Tamils of Sri Lanka - Sri Lankan Tamils