Concept:Good intercommunal relationship means peaceful and cooperative interaction between different communities.
Explanation:When communities live and work together peacefully, they build trust and reduce hostility.
This trust leads to mutual understanding and shared goals.
With peace and understanding, communities can cooperate on projects that bring growth.
Therefore, development becomes a natural result of strong intercommunal relationships.
Option A, encouraging competition among individuals, is not a community-level achievement.
Option B, curtailing rural-urban migration, is not directly caused by good intercommunal relations.
Option D, promoting national cultural festivals, is only a cultural activity, not a major communal achievement.
Hence, the most appropriate answer is the option that mentions peace, mutual understanding, and development.
Answer:C. promoting peace, mutual understanding and development