Answer:
B
Step-by-step explanation:
A: If I have the right time period (the end of Grant's Presidency) a very long line of Republican presidents were elected. Grant himself was a Republican. So from 1861 to 1884, the Republican Party was really dominant. It was interrupted somewhat by Lincoln who was affiliated with another party, but he was remembered mostly as a Republican. Grover Cleveland in 1884 broke the Republican strong hold.
B is true. The Democrats consisted mostly of white voters. They were united and had a vision for the south.
C is just not true. Few Blacks could vote, let alone take office. The first two were elected in 1870, one as a congressman and the other as a senator! Since then over 160 have served in either the senate or congress. It is not a particularly large number.
D Since I think B is unconditionally true, this must be false, but I don't know why. I cannot see how it could be so when the Republicans held the presidency for so long and the dominated Congress even longer.