Dude option {B} IS CORRECT..not option {C}

Explanation:

Atomic Radius:
Atomic radius refers to the size of an atom. It is measured from the center of the nucleus to the outermost electron shell. The atomic radius generally increases as you move down a group in the periodic table and decreases as you move across a period from left to right.

Comparison of Ga and B:
To determine whether the atomic radius of Ga (gallium) is less than B (boron) or not, we need to consider their positions in the periodic table.

Position in the Periodic Table:
Boron (B) is located to the left of gallium (Ga) in the periodic table. Boron belongs to Group 13, while gallium belongs to Group 14. Both elements are in the same period (period 3).

Trend in Atomic Radius:
As we move across a period from left to right, the atomic radius generally decreases. This is due to the increasing effective nuclear charge, which attracts the electrons more strongly and reduces the size of the atom.

Comparison of Atomic Radii:
Based on the trend in atomic radius, we can conclude the following:

1. The atomic radius of Ga is larger than B.
- This is because gallium is located to the right of boron in the periodic table, and as we move across a period from left to right, the atomic radius decreases. Therefore, the atomic radius of gallium is larger than that of boron.

2. The atomic radius of Ga is more than Al.
- This statement is incorrect because gallium (Ga) and aluminum (Al) are in the same group (Group 13) and period (period 3) of the periodic table. When elements are in the same group, their atomic radii generally increase as we move down the group. Therefore, the atomic radius of gallium is expected to be larger than that of aluminum.

3. The atomic radius of Ga is less than Al.
- This statement is correct. As mentioned earlier, the atomic radius generally increases as we move down a group. Since gallium (Ga) is located below aluminum (Al) in Group 13, the atomic radius of gallium is smaller than that of aluminum.

4. The atomic radius of Ga is equal to Al.
- This statement is incorrect. Based on the trend in atomic radius and the positions of gallium and aluminum in the periodic table, the atomic radius of gallium is expected to be smaller than that of aluminum.

Therefore, the correct statement is that the atomic radius of Ga is less than Al (option C).