The correct answer is option 'A' - Sudan.

Explanation:
Emigration refers to the act of leaving one's own country to permanently settle in another. It is worth noting that emigration is influenced by various factors such as economic opportunities, political stability, quality of life, education, and personal circumstances. While all countries experience some level of emigration, some countries are notably known for a higher number of people leaving to settle abroad. In the given options, Sudan stands out as a country with a significant emigration rate.

Reasons for Sudan's notable emigration rate:
1. Political instability: Sudan has faced prolonged periods of political instability, including civil wars and internal conflicts. These factors often lead to people seeking safety and better opportunities in other countries.
2. Economic challenges: Sudan has faced economic challenges, including high poverty rates, unemployment, and limited access to basic services. These conditions can push individuals to seek better economic prospects abroad.
3. Human rights concerns: Sudan has faced allegations of human rights abuses, which may motivate individuals to seek asylum or refuge in other countries with more favorable human rights conditions.
4. Limited opportunities: Sudan's limited infrastructure, healthcare facilities, and educational resources can lead individuals to emigrate in search of better opportunities and higher living standards elsewhere.
5. Regional conflicts: Sudan's geographical location in the Horn of Africa has made it a host to refugees from neighboring countries, such as South Sudan and Eritrea. While not classified as emigration from Sudan itself, the presence of refugees adds to the overall movement of people in the region.

It is important to note that emigration rates can vary over time and depend on various factors. While Sudan is notable for its emigration rate, it should be understood within the context of the country's specific circumstances.