The correct answer is option 1, Democratic Republic of Congo (DRC). Here is a brief explanation for each option:

1. Democratic Republic of Congo: This is the correct answer. The Democratic Republic of Congo has faced numerous instances of ethnic violence involving the Hema and Lendu communities. These conflicts have often led to the death of hundreds of people.

2. Indonesia: Indonesia has had its share of communal and ethnic violence but not specifically between the Hema and Lendu ethnic groups as they are indigenous to Democratic Republic of Congo, making this option incorrect.

3. Nigeria: Although Nigeria has been troubled by ethnic and religious conflicts, the violence between the Hema and Lendu communities has not happened here. So this is also not the correct answer.

4. Zambia: Zambia, just like the other options, has not had any reported instances of violence between the Hema and Lendu communities. Therefore, this is not the correct answer.

So, no change in the provided answer is needed, it is correct as it is.