The correct answer is option 4: South Africa. The currency of South Africa is called the Rand, and its currency code is ZAR. The Rand is the legal tender of South Africa and is widely used for both domestic and international transactions within the country. It is subdivided into 100 cents. The currency symbol for the Rand is "R".

To solve this question, we need to know the currency of each country mentioned in the options. Option 1, Burundi, does not use the Rand/ZAR as its currency. The currency of Burundi is the Burundian Franc (BIF), so option 1 is incorrect. Option 2, Libya, also does not use the Rand/ZAR as its currency. The currency of Libya is the Libyan Dinar (LYD), so option 2 is incorrect. Option 3, Sudan, also does not use the Rand/ZAR as its currency. The currency of Sudan is the Sudanese Pound (SDG), so option 3 is incorrect. Therefore, the only correct option is option 4, South Africa.