Which of the following does not use excessive coordination or subordination?
A. In the 1950s and 1960s, children's books by authors like Dr. Seuss began taking on serious social themes, and they did so without becoming too heavy-handed, but they also were quite imaginative, and the illustrations became more and more imaginative.
B. By the 1950s, children's books were more colorful and more varied in content.
C. One hundred years ago, children's books were usually printed in black and white, and they had simple illustrations (often very good), and they told stories with strong and simple moral messages.
D. Fashions in children's books have changed considerably, and what was popular one hundred years ago is not popular now, for tastes have changed, and the production techniques have also changed.