\\\\(B{ F }_{ 3 }\\\\) has a trigonal planar structure, all three \\\\(B-F\\\\) bonds lie in the same plane. Thus, the p orbitals of Boron and Fluorine become parallel.p-orbital of Boron is empty while fluorine has a lone pair. Fluorine donates its lone pair and this is called back bonding, or \\\\(p\\pi -p\\pi \\\\) bond. Resonating structures can be obtained.Since the \\\\(B{ F }_{ 3 }\\\\) molecule is highly symmetrical, it has no dipole moment. All bonds are of equal length, thus option (B) is correct.In Boron trihalides, the length of \\\\(B-F\\\\) bond would be shorter than expected for a single bond, due to \\\\(p\\pi -p\\pi\\\\) bonding.\\\\(B{ Cl }_{ 3 }\\\\) is also a trigonal planar molecule. Back bonding does not change the structure of the molecule. It simply decreases bond length \\\\(B-X\\\\) and decreases Lewis acidity of \\\\(B{ X }_{ 3 }\\\\).Thus, option \\\\((D)\\\\) is incorrect.