Why do most translators avoid referring to Gregor as a cockroach?

A. The word has many different connotative meanings, and the reader would be confused.
B. The reader would be disgusted by Gregor's transformation and would not be interested in him.
C. Avoiding the word makes the reader as confused as Gregor is about the change in his physical state.
D. The word has no meaning in the German language, and Kafka would not have used it.