William and Caroline Herschel's Map Included Four of the Following

William and Caroline Herschel's map included four of the following hypotheses in their model of the galaxy. Which one was the exception?

A) They thought that the "holes in the sky" were caused by interstellar dust clouds.
B) They proposed that the galaxy had a disk shape.
C) They provided accurate measurements of the distances to stars.
D) They placed the Sun in the center of the galaxy.
E) They found errors caused by a lack of knowledge of the interstellar medium.