If the length of the longest chord of a certain circle is 10, what is the radius of that certain circle?  Options:
A) 2.5  B) 5  C) 10  D) 15  E) 20
Longest chord of a circle is the diameter of the circle   diameter = 2 * radius   If diameter of the circle is given as 10 = 2 * 5   so radius of the circle = 5   correct answer - 5
<result>B</result>
If the length of the longest chord of a certain circle is 10, what is the radius of that certain circle?