Answer :
The correct answer is c.
Mesopotamia is known as the “cradle of civilization” mainly by the invention of writing (which is known as Cuneiform writing) in the region of Sumer.
Cuneiform is a system of writing first developed by the ancient Sumerians of Mesopotamia between 3500 and 3000 BCE, its name comes from the Latin word cuneus for 'wedge' due to the wedge-shaped style of writing.
All of the great Mesopotamian civilizations used cuneiform until it was changed by the alphabetic script at some point after 100 BCE.