Which one of the following is the standard deviation of the first 7 (1 to 7) natural numbers?

Correct option is C

​$$\textbf{Step-by-step Calculation:}1. \ \text{Given values: First 7 natural numbers: } 1, 2, 3, 4, 5, 6, 7. \\2. \ \text{Calculate the mean } (\bar{x}): \\\bar{x} = \frac{\sum x_i}{n} = \frac{1 + 2 + 3 + 4 + 5 + 6 + 7}{7} = \frac{28}{7} = 4 \\3. \ \text{Calculate } (x_i - \bar{x})^2 \text{ for each value:} \\(1 - 4)^2 = 9, \\(2 - 4)^2 = 4, \\(3 - 4)^2 = 1, \\(4 - 4)^2 = 0, \\(5 - 4)^2 = 1, \\(6 - 4)^2 = 4, \\(7 - 4)^2 = 9 \\4. \ \text{Sum of squared deviations:} \\\sum (x_i - \bar{x})^2 = 9 + 4 + 1 + 0 + 1 + 4 + 9 = 28 \\5. \ \text{Calculate variance:} \\\text{Variance} = \frac{\sum (x_i - \bar{x})^2}{n} = \frac{28}{7} = 4 \\6. \ \text{Calculate standard deviation:} \\SD = \sqrt{\text{Variance}} = \sqrt{4} = 2$$​​