As you move down a group of the periodic table how does the atomic radius of the atoms change

An atom gets larger as the number of electronic shells increase; therefore the radius of atoms increases as you go down a certain group in the periodic table of elements. In general, the size of an atom will decrease as you move from left to the right of a certain period.

Explanation:

answer; i believe that the correct answer is (a); a large rock being weathered by wind and rain;