The Holocaust was a genocide of European Jews carried out by Nazi Germany during World War II. It is estimated that approximately six million Jews, along with millions of others, including Romani people, Poles, disabled individuals, and political dissidents, were systematically murdered by the Nazis. The correct answer to the question is option 'C' - Nazi Germany.

Here is a detailed explanation of the answer:

The Holocaust and Nazi Germany:
The Holocaust was a state-sponsored, systematic persecution and annihilation of Jews in Europe by Nazi Germany and its collaborators. It was carried out between 1941 and 1945 during World War II, under the leadership of Adolf Hitler and his Nazi regime.

Nazi Ideology:
The Holocaust was a result of the Nazis' anti-Semitic ideology, which viewed Jews as a racially inferior and dangerous group. The Nazis believed in the concept of Aryan racial superiority and sought to create a pure Aryan society by eliminating Jews and other "undesirable" groups.

Persecution and Genocide:
The persecution of Jews began with discriminatory laws and policies that restricted their rights and freedoms. Jews were subjected to forced labor, ghettos, and mass deportations to concentration camps, where they faced starvation, disease, and brutal treatment. The Nazis implemented a systematic process of extermination through mass shootings, gas chambers, and crematoria.

Collaboration and Resistance:
While the Nazis were responsible for planning and executing the Holocaust, they had collaborators from various European countries. Some governments, like Vichy France, willingly participated in the persecution and deportation of Jews. However, there were also individuals and groups who resisted the Nazis and helped rescue Jews, often at great personal risk.

Legacy and Remembrance:
The Holocaust remains one of the darkest periods in human history, highlighting the depths of human cruelty and the dangers of unchecked hatred and prejudice. It led to the establishment of the Universal Declaration of Human Rights and the recognition of genocide as an international crime. Holocaust remembrance and education are crucial in ensuring that such atrocities are never repeated.

In conclusion, the Holocaust was a genocide of European Jews carried out by Nazi Germany. It was a result of the Nazis' anti-Semitic ideology and systematic persecution of Jews. The Holocaust serves as a stark reminder of the consequences of hatred, discrimination, and unchecked power.