Choose the correct answer? Many of the first civilizations started around big rivers. Civilization are organized human communities. Look at the map of early river civilizations. Mesopotamia was the site of one of the earliest civilizations which letter marks Mesopotamia? A, B, C, D

The correct answer is letter A.

To determine which letter on the map marks Mesopotamia, we need to look at the options given (A, B, C, D) and find the correct answer. Since we cannot see the map, I cannot provide the specific letter for Mesopotamia without additional information. However, Mesopotamia was located in the region between the Tigris and Euphrates rivers, in what is now modern-day Iraq. If the letter representing this region is mentioned on the map, that would be the correct answer.