Although its gray text blocks and black-and-white illustrations give it a sober mien, this one-stop resource can take the place of a dozen less________ texts.
A. exhaustive
B. interesting
C. appealing
D. original
E. educational
F. comprehensive
이 문제 중 답이 왜 A,F인지 로직 설명 부탁드립니다. 감사합니다.