In the xy-plane, the point (2, 1) is the center of a circle. The point (-2, 1) lies inside the circle and the point (2, -5) lies outside the circle. If the radius r of the circle is an integer, then r =
Choose the most appropriate option.
A) 6	B) 5	C) 4	D) 3	E) 2

Rationale: an easy way to solve this question will be just to mark the points on the coordinate plane . you ' ll see that the distance between the center ( 2 , 1 ) and the point inside the circle ( - 2 , 1 ) is 4 units ( both points are on y = 1 line so the distance will simply be 2 - ( - 2 ) = 4 ) so the radius must be more than 4 units . the distance between the center ( 2,1 ) and the point outside the circle ( 2 , - 5 ) is 6 units ( both points are on x = 2 line so the distance will simply be 1 - ( - 5 ) = 6 ) so the radius must be less than 6 units , which implies 4 < r < 6 , thus as r is an integer then r = 5 . answer : b .
Answer: B