The two circles x2 + y2 = r2 and x2 + y2 – 10x + 16 = 0 intersect at two distinct points. Then which one of the following is correct?

The two circles x2 + y2 = r2 and x2 + y2 – 10x + 16 = 0 intersect at

1.	The two circles x2 + y2 = r2 and x2 + y2 – 10x + 16 = 0 intersect at two distinct points. Then which one of the following is correct?
A.	2 < r < 8
B.	r = 2 or r = 8
C.	r < 2
D.	r > 2
Answer» B. r = 2 or r = 8