Answer :
Gerrymandering occurs when electoral districts are redrawn to create safe seats, effectively ensuring one political party's dominance in those districts. This practice, although legal, can undermine the democratic principle of fair representation unless it impinges on minority voting rights protected by the Voting Rights Act. Hence the correct option is 4) Gerrymandering; single-member districts
Gerrymandering is when state legislatures redraw district boundaries to advantage candidates of their party by creating safe seats or districts in which members of their party are likely to win by a comfortable margin. This old practice combines the name of Massachusetts governor Elbridge Gerry with the word salamander to describe the bizarre shapes these districts can often take. Despite its legality, gerrymandering is ethically questionable and has been used by both major parties to maintain or gain political power. It can only be challenged under the Voting Rights Act if it seems to dilute the votes of racial minorities.
Specific tactics used in gerrymandering include packing and cracking: packing refers to concentrating opposition voters into a few districts to win more seats with fewer votes, while cracking involves spreading opposition voters across many districts to dilute their influence. Ultimately, gerrymandering results in legislators selecting their voters rather than voters choosing their representatives, threatening the democratic process.