What Is an Example of a Class Action Lawsuit

What is an example of a class action lawsuit?

A) any case decided by the U.S. Supreme Court that affects an entire class of people
B) Bush v. Gore, which ruled on the Florida recount process in the 2000 presidential election
C) Chisholm v. Georgia, which ruled that a citizen of one state could sue another state in federal court
D) Citizens United v. Federal Election Commission, which ruled that corporations were entitled to use treasury funds for independent spending in campaigns
E) the 1.5 million current and former female Walmart employees who recently sued Walmart for sex discrimination