Best answer: B. A state is sued for intentionally creating a Congressional district with a majority African-American population.
Background/context:
The landmark case regarding voting district lines was <em>Baker v. Carr </em>(1962), which pertained to voting districts in Tennessee. The plaintiff, Charles Baker, argued that voting districts, which had not been redrawn since 1901, heavily favored rural locations over urban centers which had grown significantly since then. Joe Carr was Secretary of State for Tennessee at the time, so was named in the case in regard to voting district lines as drawn by the state legislature. The Supreme Court ruled that voting districts were not merely a political matter to be decided by legislatures, but that they were subject to review by federal courts to determine their fairness.
The matter of redrawing district lines has come up in court cases recently as some state legislatures, when dominated by one political party, have "gerrymandered" district lines to try to maintain continued prominence for their party. Legislatures dominated by one party may redraw district lines (following the US Census) in ways that favor their party's candidates maintaining an advantage. Earlier this year, lawsuits were filed against the states of Alabama, Georgia, and Louisiana, accusing those states of trying to isolate African-American voters to limit their impact on Congressional elections. According to <em>Courthouse News Service </em>(June 14, 2018), "In Georgia, Alabama and Louisiana, local lawyers filed lawsuits in federal court against each states’ Secretary of States ... alleging the Republican efforts in 2011 to redraw congressional lines left many of the minority black voters packed into one district and breaking up pockets of others."