D. A conversation between two characters is called a "Dialogue".
A legend is a caption, a title or brief explanation appended to an article, illustration, cartoon, or poster.
A key is an explanatory list of symbols used in a map, table, etc.
The correct answer here is c) to the extreme. An absolute phrase is a
phrase which includes a subject, and whereas the other possible answers
all include subjects (eyes, hands, heart) the same cannot be said of 'to
the extreme' which could be described more as a commonplace saying or
cliche rather than an absolute phrase.