Answer: Option (A) is the correct answer.
Explanation:
A group in a periodic table is represented by a column. And, when we move down a group then there occurs an increase in atomic size or atomic radii of the elements.
This is because number of electrons add into new shells which leads to increase in atomic radii of the element.
Therefore, if we say that two elements in a group have similar atomic radii then it is false.
Whereas the two elements of a group might have a high melting point.
Also the statements, the two elements both are highly reactive in oxygen and the two elements both bonds with chlorine to form a salt in a 1 to one ratio can be true for elements of the same group.
Thus, we can conclude that the statement two elements both have similar atomic radii would not support the conclusion that two elements are in the same group.
