The changes that grete and gregor's parents undergo over the course of the metamorphosis affect the plot by: a. showing that the other characters in the story are important, too. b. allowing the reader to relate to the characters and their emotions. c. making the characters seem more human and appealing. d. moving the story forward and increasing dramatic tension.

The correct answer is option D. "moving the story forward and increasing dramatic tension.". In "The Metamorphosis" by Franz Kafka, Grete and Gregor's parents had to adapt to the disappearance of Gregor, the father had to find a job at a bank, but each member of the family had to slowly changed and had its own metamorphosis. This situation help to move the story forward and also add additional dramatic tension besides of Gregor's transformation.

the father traits is what becomes more dominate the mothers is half dominate or vise versa depending on the gender.