Hey!! I believe that the answer is D. Ethnic and religious diversity!!
The Demilitarized Zone between North and South Korea was created in a. 1953. It established the end of the Korean War and it crosses the 38th parallel (but is not completely on it).
Voter registration. To vote in Arizona, one must be a citizen of the United States and a resident of an Arizona county. A voter must be 18 years or older on or before Election Day. To be eligible to vote in an election one must register at least 29 days prior to the election.
Located in South East Asia and approximately 10,000 miles away from the Continental United States the Vietnam climate and geographical plains made it hard to travel and transport supplies.
Much of Vietnam, especially the mountains is covered by dense jungle (The Embassy of the Socialist Republic of Vietnam in the United Kingdom) Has 2 major rivers used largely for transportation.
Southern Vietnam was bordered by Laos and Cambodia and Was divided by the US military into FOUR sections making communication and back up difficult. also, the United States at the time were not trained widely for jungle battle, and were extremely vulnerable for surprise attacks.
