$(1) \;CO_2:$
Since the electronegativity of Carbon is 2.5 and that of Oxygen is 3.5, Carbon-di-oxide has polar bonds.
However, the geometry of $CO_2$ is linear and hence it is not polar as the dipoles cancel out.
$(2) \;CH_2Cl_2:$
Since the electronegativity of Carbon is 2.5 and that of Hydrogen is 2.1 and that of Chlorine is 3.0, it has 2 poplar bonds $(C-Cl)$ and two that are almost nonpolar $(C-H)$.
In this case, the geometry is tetrahedral. Since the $(C-Cl)$ and $(C-H)$ bonds are different, their dipoles don't cancel out. Therefore, this molecule has dipole-dipole forces.
$(3) \; CH_4:$
Since the electronegativity of Carbon is 2.5 and that of Hydrogen is 2.1, the $(C-H)$ bonds are almost nonpolar $(C-H)$.
While the geometry is tetrahedral, the polarities will cancel out and hence this is nonpolar.
Therefore the answer is (C): Only (2) $CH_2Cl_2$ has dipole-dipole forces.