Advertisement: Anyone who thinks moisturizers are not important for beautiful skin should consider what happens to the earth, the skin of the world, in time of drought. Without regular infusions of moisture the ground becomes lined and cracked and its lush liveliness fades away. Thus your skin, too, should be protected from the ravages caused by lack of moisture; give it the protection provided by regular infusions of Dewyfresh, the drought-defying moisturizer. The Dewyfresh advertisement exhibits which one of the following errors of reasoning? ['It relies on an analogy between two things that are insufficiently alike in the respects in which they would have to be alike for the conclusion to be supported.', 'It treats something that is necessary for bringing about a state of affairs as something that is sufficient to bring about that state of affairs.', 'It treats the fact that two things regularly occur together as proof that there is a single thing that its the cause of them both.', 'It relies on the ambiguity of the term "infusion, "which can designate either a process or the product of that process.']