The correct option is D Ethnic conflict in Serbia
Transition to democracy in Nepal, one-party rule in China, fraudulent elections in Mexico, military rule in Pakistan, and women’s rights in Saudi Arabia are examples of Foundational challenges. Ethnic conflict in Serbia, ethnic conflict in Sri Lanka, sectarian conflict in Northern Ireland, Apartheid regime in South Africa, sectarian conflict in Iraq, and the conflict between linguistic groups in Belgium were the examples of Challenge of expansion.