[" Al and Ga have nearly the same covalent radii,"],[" because of "],[" (A) Greater shielding effect 's' electrons "],[" of 'Ga' atoms "],[" (B) poor shielding of 's' electrons of 'Ga' "],[" atoms "],[" (C) poor shielding effect of 'd' electrons "],[" of 'Ga' atoms "],[" (D) greater shielding effect of 'd' "],[" electrons of 'Ga' atoms "]