Answer:
[tex]\boxed {\boxed {\sf B. \ Iodine }}[/tex]
Explanation:
Atomic radius is the measurement from the nucleus to the outer edge of the electron cloud.
As you go down a group (vertically) the atomic radius increases because more electron shells are added. As you go across a period horizontally, the atomic radius decreases.
If we look at the halogens group (17), we see they follow this order from top to bottom:
F - Fluorine
Cl - Chlorine
Br - Bromine
I - Iodine
Since it increases down the group, iodine must have the largest atomic radius.
