Which of the following statements are correct?
a) Indian nationalism sought to balance the principles of unity and diversity.
b) European countries see cultural diversity as a threat to the nation.

Both statements are correct.

Indian nationalism sought to balance the principles of unity and diversity. The nation would not mean the negation of the region. In this sense, the Indian approach was very different from the one adopted in many European countries where they saw cultural diversity as a threat to the nation.