The Circle or Ellipse Shown in the Calculator-Generated Graph Was $y_{1}$

Multiple Choice

The circle or ellipse shown in the calculator-generated graph was created using function mode with a square viewing window. What are the two functions $y_{1}$ and $y_{2}$ that were used to obtain the graph whose equation is given?
- $\frac{x^{2}}{16}+\frac{y^{2}}{25}=1$

A) $y_1=5 \sqrt{1+\frac{x^{2}}{16}}, y_2=-5 \sqrt{1+\frac{x^{2}}{16}}$

B) $\mathrm{y}_{1}=5 \sqrt{1-\frac{\mathrm{x}}{4}}, \mathrm{y}_{2}=-5 \sqrt{1-\frac{\mathrm{x}}{4}}$

C) $y_{1}=5 \sqrt{1-\frac{x^{2}}{16}}, y_{2}=-5 \sqrt{1-\frac{x^{2}}{16}}$

D) $y_{1}=5 \sqrt{1-\frac{x^{2}}{4}}, y_{2}=-5 \sqrt{1-\frac{x^{2}}{4}}$