Final answer:
Humans' preference for fatty foods is likely an adaptation that has become a liability in modern times, evidencing how traits selected for by natural selection in past environments can become detrimental in new contexts.
Step-by-step explanation:
The question you've asked is related to why humans may prefer fatty substances, and the correct answer is that humans' taste preferences for fatty substances may be an example of c. an adaptation that has become a liability. Throughout human evolution, a preference for high-fat foods would have provided significant survival advantages due to their high energy content. This trait likely became widespread in the population through natural selection, because individuals with a preference for calorie-dense foods would have had more energy to survive, reproduce, and pass on their genes.
However, in modern times, where high-fat foods are readily available and lifestyle changes mean less physical activity, this once beneficial adaptation can lead to health issues such as obesity and heart disease. Hence, it can be considered a 'liability' or a disadvantage in today's world. This phenomenon is part of population genetics and necessitates an understanding of the selective forces that may be operating on a given population.