Ethiopia and Somalia fought wars over a region called Ogaden.

Background:
Ogaden is a region in the southeastern part of Ethiopia, which is mostly inhabited by ethnic Somalis. After Ethiopia gained independence from Italy in 1941, it claimed Ogaden as part of its territory. However, Somalia also claimed Ogaden based on historical and ethnic grounds, as it was once part of the Somali Empire. Thus, the two countries had a long-standing dispute over the region.

First War (1977-78):
The first war between Ethiopia and Somalia over Ogaden started in 1977 when Somalia invaded Ethiopia. Somalia hoped to annex Ogaden and unite all Somali-inhabited areas under one state. Ethiopia, which was backed by the Soviet Union, fought back and regained control of the region after a year of fighting. The war resulted in the deaths of thousands of people and left Ogaden in ruins.

Second War (1988-91):
The second war between Ethiopia and Somalia over Ogaden started in 1988 when Somalia, which was undergoing civil war, once again invaded Ethiopia. This time, Ethiopia was backed by the United States and the Soviet Union. The war ended in 1991 when the Somali government collapsed, and Ethiopia regained control of Ogaden.

Current Situation:
Today, Ogaden remains part of Ethiopia, and Somalia has recognized Ethiopia's sovereignty over the region. However, there are still tensions between the two countries, and the issue of Ogaden's status remains unresolved. Some ethnic Somalis in Ogaden continue to demand autonomy or independence from Ethiopia, and there have been sporadic clashes between the Ethiopian military and Somali militias in the region.

(Correct Option:- B, Ethiopia and Somalia)

In 1977 Ethiopia and Somalia engaged in a brief territory conflict over the Ogaden region situated between and claimed by both nations. This conflict however held significance greater than most territorial disputes because Ethiopia was backed by the Soviet Union and Somalia was supported by the United States, thus bringing the Cold War to eastern Africa.