The total number(s) of stable conformers with non-zero diple moment for the following compound is/are

The total number(s) of stable conformers with non-zero dipole moment for the following compound is (are) .

The total number(s) of stable conformers with non-zero dipole moment for the following compound is (are) .

The moecule with non-zero dipole moment is -

The total number of conformations of ethane is:

The most stable conformation of the following compound is :

The most stable conformation of the following compound is :