Consumer advocate: A recent study concluded that top-loading washing machines are superior overall to front-loaders. But front-loaders have the controls and access in front. This is more convenient for wheelchair users, some of whom find it highly inconvenient to remove laundry from top-loaders. So for some consumers front-loaders are superior. Which one of the following is an assumption upon which the consumer advocate's argument depends? ['For some consumers the convenience of front- loaders outweighs the advantages of top-loaders in assessing which is superior.', 'Convenience is the only important factor in determining which type of washing machine is superior.', 'Retrieving clothes from front-loaders is inconvenient for people who are not wheelchair users.', 'Retrieving clothes from a top-loader is convenient for people who do not use wheelchairs.']