Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions 17.

++ Viet Nam is home to 54 ethnic groups, each with its own unique culture. Their diversity adds richness to our country's heritage _____.
a. Many groups have their own traditional costumes, often with intricate patterns and vibrant colours.
b. These groups also have distinct customs, festivals, and folk music that reflect their way of life.
c. Moreover, they usually live in different regions, from the high mountains to the vast deltas.