Express the Indicated Roots of Unity in Standard Form a $1+0 \mathrm{i}$

Multiple Choice

Express the indicated roots of unity in standard form a + bi.
-Seventh roots of unity

A) $1+0 \mathrm{i}$
$$\begin{array}{l}\cos \frac{2 \pi}{7}+i \sin \frac{2 \pi}{7} \approx 0.62+0.78 i \\\cos \frac{4 \pi}{7}+i \sin \frac{4 \pi}{7} \approx-0.22+0.97 i \\\cos \frac{6 \pi}{7}+i \sin \frac{6 \pi}{7} \approx-0.90+0.43 i \\\cos \frac{8 \pi}{7}+i \sin \frac{8 \pi}{7} \approx-0.90-0.43 i \\\cos \frac{10 \pi}{7}+i \sin \frac{10 \pi}{7} \approx-0.22-0.97 i\end{array}$$

B) $\begin{array}{l}\text { } 1+0 i \\\cos \frac{2 \pi}{7}+i \sin \frac{2 \pi}{7} \approx 0.62+0.78 i \\\cos \frac{4 \pi}{7}+i \sin \frac{4 \pi}{7} \approx-0.22+0.97 \mathrm{i} \\\cos \frac{6 \pi}{7}+i \sin \frac{6 \pi}{7} \approx-0.90+0.43 \mathrm{i} \\\cos \frac{8 \pi}{7}+i \sin \frac{8 \pi}{7} \approx-0.90-0.43 \mathrm{i} \\\cos \frac{10 \pi}{7}+i \sin \frac{10 \pi}{7} \approx-0.22-0.97 \mathrm{i} \\\cos \frac{12 \pi}{7}+i \sin \frac{12 \pi}{7} \approx 0.62-0.78 \mathrm{i}\end{array}$


C) $1+0 i$
$$\begin{array}{l}\cos \frac{2 \pi}{7}+i \sin \frac{2 \pi}{7} \approx 0.62+0.78 i \\\cos \frac{4 \pi}{7}+i \sin \frac{4 \pi}{7} \approx-0.22+0.97 i \\\cos \frac{6 \pi}{7}+i \sin \frac{6 \pi}{7} \approx-0.90+0.43 i \\\cos \frac{8 \pi}{7}+i \sin \frac{8 \pi}{7} \approx-0.90-0.43 i \\\cos \frac{10 \pi}{7}+i \sin \frac{10 \pi}{7} \approx-0.22-0.97 \\\cos \frac{12 \pi}{7}+i \sin \frac{12 \pi}{7} \approx 0.62-0.78 i\end{array}$$

D) $1+0 i$
$$\begin{array}{l}\cos \frac{\pi}{7}+i \sin \frac{\pi}{7} \approx 0.90+0.43 i \\\cos \frac{2 \pi}{7}+i \sin \frac{2 \pi}{7} \approx 0.62+0.78 i \\\cos \frac{3 \pi}{7}+i \sin \frac{3 \pi}{7} \approx 0.22+0.97 i \\\cos \frac{4 \pi}{7}+i \sin \frac{4 \pi}{7} \approx-0.22+0.97 \mathrm{i} \\\cos \frac{5 \pi}{7}+i \sin \frac{5 \pi}{7} \approx-0.62+0.78 \mathrm{i} \\\cos \frac{6 \pi}{7}+i \sin \frac{6 \pi}{7} \approx-0.90+0.43 \mathrm{i}\end{array}$$