Very tough geography quiz?

Do you have a friend/relative/spouse who thinks he/she is the bee's knees of geography knowledge?  I offer you a quiz question that will bring them to their knees.Just one question: What independent country has the "highest lowest point" ?
Not the highest point, mind you.  We're not talking Nepal or Tibet.  We want the country whose lowest point is higher than any other country's lowest point.   Nepal, for example, has "southern lowland plains."
The correct answer is a country which exists "entirely above 1,000m."  To be more precise: "Its lowest point of 1,400 meters (4,593 ft) is thus the highest in the world. Over 80% of the country lies above 1,800 meters (5,906 ft)."
Where is this country?
I knew instantly.
Answer here.