"When you are reading, you are essentially saying things out loud in your head," said Cutting. "If you have decreased integrity of white matter in this area, the front and back part of your brain are not talking to one another. This would affect reading, because you need both to act as a cohesive unit."
D: this implies that a language should be able to be spoken.
Heaps of silent or unpronouncable consonants could not be 'sounded out' in one's mind.