In general, the most powerful aspect of the genre of six-word stories is that stories written with only six words
a. force the reexamination of long-held beliefs.
b. greatly influence readers' writing styles.
c. demand intellectual exploration.
d. encourage active contemplation and questioning.

D

Explanation:

One of the most famous six-word stories is: For sale, baby shoes, never worn. Six-word stories are the perfect way of emotional expression. The writer can write it and leave it for interpretation. Therefore it allows the reader to think about the story and tries to intuit and understand what it means based on his or her shared experience. So encouraging contemplation and questioning is the correct option (D).