Question

S is the set of current U.S. Senators from states that begin with A

Answer 1

Answer:

  see below

Step-by-step explanation:

The "roster method" means you simply list them all:

  {John Boozman, Doug Jones, Martha McSally, Lisa Murkowski, Tom Cotton, Richard C. Shelby, Kyrsten Sinema, Dan Sullivan}

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There are no senators from these states with the same name, so repeated elements is not an issue here.