A) "Was originally in favor of slavery, but now is that party that is viewed as championing rights of minorities." In fact, they were in favor of slavery, and nowadays they look after minority groups such as immigrants, women, African Americans, etc.
C) "Had the only presidential candidate that was elected for three consecutive terms.". Franklin Delano Roosevelt was elected President for three consecutive terms.
D) "Held control of the Senate for over 30 years." The Democratic party has controlled the Congress and the White House for over 30 years in the past 100 years.
The famous Wade-Davis bill opposed the "10 percent plan" of Lincon. The Wade–Davis Bill (1864) was proposed to reconstruct the South. In contrast to the Ten Percent Plan, the bill ensured the re-admittance to Union on majority in every Southern state for taking the oath.
A. What A basically says is that the British allowed African American people to vote, since they where a minority and would never be too influential in elections.
I have to say B. The rest were concepts made in Greece, by Greek philosophers, politicians, or mathematicians. An example for an advancement in math is the Pythagorean Theorem. I hope this helps!