Hello, I could probably answer it more surely if the question was provided in its original format. But for how it was presented, I believe the answer would be C. A callout.
A callout (or call-out) in publishing is a short excerpt within a bigger text, somehow highlighted to call the reader's attention out to that part, specially. It can be a short string of text with its words connected by lines, dots, arrows, or similar, a sentence in bold separated from the text, or written in a different format, usually in a larger font. - This one is very common in magazines and newspapers. (and I believe this is the type that was presented on this excerpt original format).
Answer:
<h3>If something changes or is done gradually, it changes or is done in small stages over a long period of time, rather than suddenly. Electricity lines to 30,000 homes were gradually being restored yesterday. Synonyms: steadily, slowly, moderately, progressively More Synonyms of gradually.</h3>
<h2>Hope it helps you.</h2>
