Answer:
All circles are similar to each other.
Step-by-step explanation:
Circles are <u><em>congruent</em></u> if they have the same radius, regardless of where their centers are located.
Then all circles can't be congruent, because not all of them have the same radius.
Circles are <u><em>concentric</em></u> if they have the same center. And not all circles have the same center.
And circles can't be <u><em>parallels</em></u>. Parallelism is a relationship that is established between lines or planes.
Then, the correct option is all circles are <u>similar</u> to each other. They all have the same shape although they can be of different sizes, have different centers, and different radius.