Carbon tetrachloride does have not dipole moment because of

Its regular tetrahedral structure

Carbon tetrachloride \((CCl_4)\) is a non-polar molecule because it has a regular tetrahedral structure. In a regular tetrahedral structure, the four \(C-Cl\) bonds are arranged in such a way that the dipole moments of the individual bonds cancel each other out. This is because the dipole moments of the \(C-Cl\) bonds are equal in magnitude but opposite in direction.

The other options are not correct. The planar structure of \(CCl_4\) would not prevent it from having a dipole moment, and the similar sizes of carbon and chlorine atoms would not have a significant effect on the dipole moment of the molecule. The similar electron affinities of carbon and chlorine atoms would also not have a significant effect on the dipole moment of the molecule.

Therefore, the correct answer is (2) Its regular tetrahedral structure.