The correct statement regarding ethane conformation is :

Rotation around carbon-carbon bond in ethane molecule is not possible, because ethane molecule contains both sigma $$(\sigma)$$ bond and pi $$(\pi)$$ bond between the carbon and carbon and ethane has very high boiling point.

Rotation around carbon-carbon bond in ethane molecule is not possible, because ethane molecule contains a pi $$(\pi)$$ bond between the carbon and carbon and ethane has very low melting point.

Rotation around carbon-carbon bond in ethane molecule is not possible, because ethane molecule contains both sigma $$(\sigma)$$ bond and pi $$(\pi) bond between the carbon and carbon.

Rotation around carbon-carbon bond in ethane molecule is possible because of cylindrical symmetry of sigma (\sigma)$$ bond between carbon-carbon atoms