Why was D Day important? 1. It was the day Allies would launch the largest water-to-land invasion and it successfully started pushing German troops back toward Germany
2. It allowed Germany to take over France
3. It helped Allies overcome Japan
4. It was the plan for mass murder of all European Jews and other people Hitler called “undesirables” during WWll

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."

well this isn't a question but if you are asking if it is true or false it is, true.