This choice is incorrect because it focuses on the premise that people consume extra calories when they eat “fake fat” products. While this premise suggests that people take in a fixed number of daily calories, it is not the argument’s main conclusion.

This answer misstates the argument’s main conclusion. The argument concludes that consumers who expect “fake fat” foods to help them lose weight will likely be disappointed, not those who expect the foods to be more nutritious.

The dietician doesn’t compare “fake fat” to other foods regarding its potential to cause obesity. Since the dietician doesn’t make this comparison, any opinions about “fake fat” causing obesity cannot be considered part of the dietician’s conclusion.

This is a good paraphrase of the argument's main conclusion. The stimulus notes that consumers who switch to "fake fat" to lose weight will be disappointed because, as this answer explicitly states, the "fake fat" in foods is unlikely to help consumers lose weight.

The stimulus doesn’t make this argument. The dietician says that “fake fat” usually doesn’t help people lose weight but does not discuss whether it tastes like real fat. As the main conclusion must match the argument in the stimulus, it can’t be about something not mentioned.