What's a certain indicator that a molecule is polar?

the molecule has a nonpolar covalent bond and the dipole is cancelled due to symmetrical arrangement of atoms

the molecule has a polar covalent bond and the dipole is cancelled due to symmetrical arrangement of atoms

the molecule has a nonpolar covalent bond and the dipole is established due to asymmetrical arrangement of atoms

the molecule has a polar covalent bond and the dipole is established due to asymmetrical arrangement of atoms