Answer:
[tex]\fbox{\begin{minipage}{10em}Option C is correct\end{minipage}}[/tex]
Explanation:
A circle whose center is [tex](a, b)[/tex] and radius [tex]r[/tex], has equation:
[tex](x - a)^{2} + (y - b)^{2} = r^{2}[/tex]
The center of circle is given as origin [tex](0, 0)[/tex], therefore:
[tex]a = 0\\b = 0[/tex]
This circle passes [tex](3, 0)[/tex], then the radius of circle is the distance [tex](d)[/tex] between origin [tex](0, 0)[/tex] and [tex](3, 0)[/tex]
[tex]d = \sqrt{(0 - 3)^{2} + (0 - 0)^{2} } = \sqrt{3^{2} } = 3[/tex]
=> [tex]r = d = 3[/tex]
Substitute [tex]a[/tex], [tex]b[/tex], and [tex]r[/tex] back into original equation:
[tex](x - 0)^{2} + (y - 0)^{2} = 3^{2}[/tex]
or
[tex]x^{2} + y^{2} = 9[/tex]
Hope this helps!
:)