Joanna: The only way for a company to be successful, after emerging from bankruptcy, is to produce the same goods or services that it did before going bankrupt. It is futile for such a company to try to learn a whole new business. Ruth: Wrong. The Kelton Company was a major mining operation that went into bankruptcy. On emerging from bankruptcy, Kelton turned its mines into landfills and is presently a highly successful waste-management concern. Ruth uses which one of the following argumentative techniques in countering Joanna's argument? ['She undermines a claim by showing that it rests on an ambiguity.', 'She offers an alternative explanation for a phenomenon.', 'She presents a counterexample to a claim.', 'She establishes a conclusion by excluding the only plausible alternative to that conclusion.']