Mikhail Gorbachev is usually credited for helping end the cold war.
Anniversary Reaction is the correct answer.
Trauma anniversary, also known as anniversary reaction, is the reocurring of an emotional or physical distress that happened around the same time in the year (or years) before. People who go through this reaction can experience an increase of distress since it reactivates the feelings or emotions felt in that past traumatic experience.
Both C and D answers show uncorrect statements about the 2010 Haiti earthquake.
Answer C states that the quake registered at 7.8 on the Richter scale, but that's not true. The earthquake occurred inland on January 12, 2010, approximately 15 km southwest of Port-au-Prince and at a depth of 10 km at 16:53 local time. It recorded 7.0 on the Richter scale.
Answer D affirms that the death toll was less than 1,000, but this is also incorrect. The effects caused on this country were devastating. The bodies recovered on January 25 exceeded 150,000, calculating that the death toll would exceed 200,000. The final data of those affected were released by Prime Minister Jean-Max Bellerive on the first anniversary of the earthquake, the January 12, 2011, stating that 316,000 people died in the earthquake, 350,000 more were injured, and more than 1.5 million people were left homeless.
It killed more than 1/3 of Europe’s population. Because so many people died there was very little slaves. The slaves moved to cities where they would get payed to work. Because there was no slaves working in homes the manor system in Europe fell apart and cities began to grow.