How to know if elements have about the same atomic radius

The elements in which of the following have most nearly the same atomic radius?
A) Be, B, C, N
B) Ne, Ar, Kr, Xe
C) Mg, Ca, Sr, Ba
D) C, P, Se, I
E) Cr, Mn, Fe, Co

I know the periodic trend for atomic radius, but I still cannot answer this question. I thought the answer might be D since the elements go in a diagonal and the elements all the answer choices go either horizontally or vertically.

But the correct answer is E. Why?

It's E because they are all transition metals and in the same row, close to each other. THey have the same charges.

P has more valence electrons than C, Se has more than P, I more than Se, so the atomic radius are totally different.