Final answer:
Rudolfo A. Anaya's essay “A Celebration of Grandfathers” suggests that the greatest threat to old values is the erosion of traditional familial relationships and cultural heritage due to modern societal changes.
Step-by-step explanation:
In the essay “A Celebration of Grandfathers,” by Rudolfo A. Anaya, one of the greatest threats to losing old values is identified as the rapid change in modern culture and lifestyle, which leads to a decline in traditional familial relationships and appreciation of heritage. Anaya highlights the importance of grandmothers and other elderly family members in preserving these values, suggesting that their stories and guidance play a vital role in sustaining cultural heritage. He expresses concern that without this intergenerational transfer of wisdom, society risks adopting values that are not inherently their own, leading to a loss of cultural identity.