Correct Option (D)
This option accurately identifies the most rational and crucial message conveyed by the passage. The text highlights multiple negative consequences of industrial meat production, including animal cruelty, the emergence of health pandemics like avian flu, and critically, the immense water consumption (15,000 litres per kilogram of meat). These factors collectively point to the environmental unsustainability of such practices, making it the overarching concern presented.
Incorrect Options:
Option (A): The passage details the negative consequences of industrial meat farming, such as cruelty, health risks, and high water intensity. It does not suggest that this method is cheap or suitable for providing protein nutrition, especially to poor countries; rather, it implies the opposite through its critique.
Option (B): While the passage explicitly mentions "cruel and shocking conditions" for animals, implying a violation of ethical treatment, this point is a specific aspect of a broader critique. The central message extends beyond animal welfare to encompass significant environmental costs and public health risks, which are more comprehensively addressed by the concept of unsustainability.
Option (C): The passage critically examines the detrimental impacts of industrial meat production. However, it does not advocate for an immediate cessation or ban of these practices. The language used critiques the current methods and their consequences, but it does not propose an extreme measure like an immediate stop.