Ka Shad Nongkrem, a major Khasi festival, includes dances that:

Celebrate the harvest
Honor the tribal goddess
Imitate the movements of birds
Reenact mythical battles

The correct answer is: a) Celebrate the harvest.

Ka Shad Nongkrem is a major Khasi festival that takes place in the month of November. It is a time for the Khasi people to celebrate the harvest and to honor the tribal goddess, Ka Law Kyntang. The festival includes a number of rituals and ceremonies, as well as dances and music.

The dances performed during Ka Shad Nongkrem are all related to the harvest. They are performed by groups of men and women, and they often involve the use of props such as drums, bells, and masks. The dances are a way for the Khasi people to express their gratitude for the harvest and to ask for the continued blessing of the tribal goddess.

The other options are incorrect because they do not accurately describe the dances performed during Ka Shad Nongkrem. Option b) is incorrect because the festival does not honor the tribal goddess. Option c) is incorrect because the dances do not imitate the movements of birds. Option d) is incorrect because the dances do not reenact mythical battles.