For this problem, we have three circles with different radii. We need to determine which circles are similar and point out the reason for our statement.
Every circle has the same shape, the only thing that sets them apart is the radii. Since we can represent the relationship between the radii as fractions, then all circles are similar. Due to this, the only correct option is the second one. "Circle 1 is similar to both circle 2 and circle 3".