Which supreme court case in 1869 resolved the debate over whether states can secede from the union?

The case was "Texas v white".

Texas v. White, (1869), U.S. Supreme Court case in which it was held that the United States is "an indestructible union" from which no state can withdraw. In 1850 the territory of Texas got $10,000,000 in government bonds in settlement of boundary claims. In 1861 the state withdrew from the Union and joined the Alliance. In 1862 the confederationist administration of the state exchanged the bonds to private people in installment for Confederate military supplies. After the Civil War the Reconstruction state government filed a suit in the Supreme Court trying to recoup the bonds, at that point held by citizens of different states.

Ithink the answer is b.)

It developed as a reaction to the impact of european colonialism in africa on peoples of african descent. in the  mid-20th century, activists in africa adopted pan-africanism as a rallying cry for independence from colonial rule. some african pan-africanists sought to unite the continent as one independenthope it was useful