An active reader could say all of the following phrases while reading, including: D. "I didn't know that."
What reading is this
Active reading involves engaging with the text, which often includes moments of surprise or realization about the content being read. Expressing "I didn't know that" signifies an active reaction to new information encountered while reading, indicating the reader's engagement and interest in the material.
Therefore, an active reader could indeed say this phrase during the reading process.