So you have a choice of the three to explore how continuity and change come about in the story. Thematically, continuity and change are seen as coexisting, though that might seem paradoxical. To see this theme, you need to look into the elements of the text that are juxtaposed to one another.

For instance, look at the plot point of the conflict between traditional native burial practices and Roman Catholic funeral rites. The native burial is shown to be very specific, involving things like facial paint when Teofilo is found:

Across the brown wrinkled forehead he drew a streak of white and along the high cheekbones he drew a strip of blue paint. . .

The burial also includes the spreading of things to carry him into the afterlife like cornmeal. This action shows the idea of continuity in the story, a continuing of traditional practices and spirituality despite the prevalence of Roman Catholicism in the area and among the Native Americans. The change is in the integration of Roman Catholicism into the burial practices.

Father Paul is the Roman Catholic priest who serves the native community in the area. He is aghast when told that they are going to do a traditional burial, and the conflict between the Church and traditional native spirituality is apparent in the conversation between him and Leon at the end. To understand how continuity and change coexist among the Native Americans in the story, it is important to see how Father Paul struggles with the request that he sprinkle holy water on Teofilo’s body. The priest represents the change, partially accepted and embraced into the native culture. He represents change precisely because the Roman Catholicism he brings is new and different. Despite representing change, he assimilates into the continuity of native tradition by aiding in the bringing of rainclouds by Teofilo, their grandfather, through the sprinkling of holy water. Despite the change, continuity continues, and even if they seem opposed, they are brought together in harmony.

The setting, an Indian reservation in the Southwest, is an integral part of Silko's story.  The dryness and the cold serve to create the feeling of isolation which brings both problems and peace for its Native American inhabitants. 

The vivid imagery immediately makes the reader "see" what the characters see and feel what they feel.   For example, Leon and Ken find the dead elder beneath "(t)he big cottonwood tree stood apart from a small grove of winterbare cottonwoods which grew in the wide, sandy, arroyo" and "the wind pushed gray dust down the narrow pueblo road. The sun was approaching the long mesa where it disappeared during the winter." 

As for continuity, for the Native Americans, the reservation is their last "home" in the U.S. It is important to pay proper respect for the elder and to assure the success the future generations (his proper burial to the next world will ensure the rain). 

The priest might be said to represent change.  The Franciscans (as well as other relgious sects) tried to change Native American religious practices.  Many acquiesced, as shown here in the fact that the characters see that the elder has a "proper" Catholic burial as well as a Native American funeral.  The change is not complete, and for most, it never will be.