The earliest surviving Greek inscriptions written in an alphabet date from the eighth century B.C. Some of these inscriptions are written from right to left, others from left to right. The alphabet they employ clearly derives from Phoenician writing, but by the eighth century B.C., Phoenician was consistently written from right to left and had been for about two centuries. Therefore, the Greeks must have adopted alphabetic writing no later than the tenth century B.C.
Which of the following is an assumption on which the argument depends?
A. Greek inscriptions from the eighth century B.C. that are written from right to left were not translations of Phoenician inscriptions.
B. In Greece, the adoption of an alphabetic writing system supplanted a writing system in which Greek was written from right to left.
C. When the Greeks adopted alphabetic writing, they also adopted the Phoenician practices of the time with respect to the direction in which texts were written.
D. After adopting alphabetic writing, the Greeks had no exposure to Phoenician inscriptions for at least two centuries.
E. Apart from Greek, all languages whose alphabets derived from Phoenician writing were consistently written from right to left.