Columnist: People should avoid using a certain artificial fat that has been touted as a resource for those whose medical advisers have advised them to reduce their fat intake. Although the artificial fat, which can be used in place of fat in food preparation, has none of the negative health effects of fat, it does have a serious drawback: it absorbs certain essential vitamins, thereby preventing them from being used by the body. In evaluating the columnist's position, it would be most useful to determine which of the following? ['Whether the vitamins that the artificial fat absorbs are present in foods that contain the fat', "Whether increasing one's intake of the vitamins can compensate for the effects of the artificial fat", 'Whether there are any foods that cannot be prepared using the artificial fat as a substitute for other fats', 'Whether having an extremely low fat intake for an extended period can endanger the health']