Explanation

In moving down to the halogen group E.N. decreases hence Iodine has the lowest electronegativity.

DETAIL ANSWER:

 iodine has the lowest electronegativity.

Fluorine has the highest electronegativity followed by chlorine and bromine,

and then with the least reactivity, we have iodine, among the given options.

Hence, option D is correct.

Note: The noble gases i.e. group 18 elements have no electronegativity.