The X molecule has a Y structure, and a large number of atoms are connected in series. A substance composed of the molecule has a strong thermal conductivity in the same type of substance. Obviously, the inclusion of a large number of atoms in the molecule makes the substance extremely strong. Essential for thermal conductivity. Which of the following, if true, would most weaken the conclusion? ['Some molecules have other structures, they also have a large number of atoms in series, and have strong thermal conductivity.', 'Some substances do not have strong thermal conductivity, but their molecules contain a large number of atoms.', 'Some substances have strong thermal conductivity, but their molecules do not have a Y structure.', 'Some substances do not have strong thermal conductivity, but their molecules have similar structures.']