1. **State the problem:** We have a seminar with 5 students classified as freshman, sophomore, junior, or senior. The bar graph shows 1 freshman, 2 sophomores, 0 juniors (omitted bar), and 1 senior. 2. **Calculate the total number of students who are not juniors:** The number of non-juniors is $1 + 2 + 1 = 4$ students. 3. **Calculate the percentage of students who are not juniors:** Use the formula for percentage: $$\text{Percentage} = \frac{\text{Number of non-juniors}}{\text{Total number of students}} \times 100$$ Substitute values: $$= \frac{4}{5} \times 100 = 80\%$$ 4. **Answer for part (a):** The percentage of students who are not juniors is 80%, so the correct choice is D. 5. **Find the number of juniors:** Since total students are 5 and non-juniors are 4, juniors = $5 - 4 = 1$ student. **Final answers:** (a) 80% (b) 1 student