Which element has the greatest average atomic mass?
a. iodine
b. bromine
c. tellurium
d. krypton

The question says, 'which element has the greatest average atomic mass. The correct option is C. The atomic mass of an element is the summation of the number of neutrons and protons that are present in the element. Out of the options given, tellurium has the highest atomic mass which is 127.6. The atomic mass of the other options are less than this.

it's c. elements are placed in rows based on how may valencies electrons have.

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter