The correct answer is A. This white supremacist organization used the name to mock the Republicans who had "waved the bloody shirt" to remind people of Confederate crimes.
Step-by-step explanation:
The term "Red Shirts" first originated during one speech of Benjamin Franklin Butler who stated he had held a shirt with the blood of a northerner and this was the result of the actions of the Ku Klux klan (extremist group from the south), which was proven as false. From there, the term "waved the bloody shirt" was applied to describe emotional speeches against Southerners or Democrats because most Republicans (Northerners) indirectly or directly blamed Democrats in the South for the death of northern soldiers and other Confederate crimes.
Additionally, in response to this, groups of people in the South began to wear the "Red Shirts" to moke of Republicans. This was the origin of the "Red Shirts" group that was a supremacist organization against the reconstruction and the ideologies promoted by Republicans. Thus, the option that best describes the origin of the term is A.