The correct answer is B. Anti-immigrant sentiment and social Darwinism
Step-by-step explanation:
Eugenics is an ideology that argues society can be improved genetically. Additionally, the main way to achieve this is by excluding or even exterminating those that are "unfit". This was applied in Germany during the Second World War which led to the extermination of thousands of jews and others such as people with disabilities because they were considered unfit.
One of the factors that contributed to this were the ideas of social Darwinism that proposed only those with desirable traits should prevail due to natural selection, which was used as a support to persecute those considered to have undesirable traits. Additionally, this ideology was promoted by strong anti-immigrant sentiments because many Jews were immigrants or descended from immigrants and many Germans did not agree with these as Jews had a strong influence in business and other areas.