Read the following fragment.

Researchers in text comprehension have applied an information-processing analogy to understanding how people think, learn, and remember what they read.

I - When a person reads, two aspects of this “human information processing system” continuously interact.

II - When the reader focuses primarily on what he or she already knows, this is called a concept-driven or “top-down” mode.

III - On the other hand, when the reader relies primarily on textual features and information to comprehend, this is called a data-driven or “bottom-up” mode.

IV - In other words, the reader is constantly noticing parts of the text and comparing that sample with what he or she did not know.

(Mikulecky, Beatrice S., Teaching Reading in a Second Language)

Choose the right option according to the context.