Citizens are required to be A: born in the United States
B: involved in the military
C: loyal to the federal government
D: members of a charitable organization

I think C, but maybe none of the above. (Depending on the strict definition of "Loyal".  You have to follow Federal laws though so I think it is C.

Explanation:

You do not need to be born in the USA to be a citizen, you can become a naturalized citizen through a legal immigration process, or marriage, or if your parents are both citizens you are automatically a citizen when you are born.

You do not need to be involved in the military to be a citizen.

You can't be against the federal government, or commit treason so I think it is C.

Being a member of a charitable organization is optional and not required for citizenship,

answer: secession

secession, as it applies to the outbreak of the american civil war, comprises the series of events that began on december 20, 1860, and extended through june 8 of the next year when eleven states in the lower and upper south severed their ties with the union. the first seven seceding states of the lower south set up a provisional government at montgomery, alabama. after hostilities began at fort sumter in charleston harbor on april 12, 1861, the border states of virginia, arkansas, tennessee, and north carolina joined the new government, which then moved its capital to richmond, virginia. the union was thus divided approximately on geographic lines. twenty-one northern and border states retained the style and title of the united states, while the eleven slave states adopted the nomenclature of the confederate states of america.

explanation: