Of the three sampling plans above, which do you think would be the most unbiased? O A. The United States is partitioned into the fifty states. Ten states are selected and every adult in each of the chosen states is surveyed. O B. The survey is mailed to 50,000 randomly selected adults and the first 2500 responses are used. O C. A complete list of all 241,472,385 adults in the United States is arranged alphabetically and every 150,000th person is surveyed