Read the following passage and answer the item that follows the passage. Your answer should be based on the passage only.As we look to 2050, when we will need to feed two billion more people, the question of which diet is best has taken on new urgency. The foods we choose to eat in the coming decades will have dramatic ramifications for the planet. Simply put, a diet that revolves around meat and dairy, a way of eating that is on the rise throughout the developing world, will take a greater toll on the world's resources than one that revolves around unrefined grains, nuts, fruits and vegetables.What is the critical message conveyed by the above passage?

• A. Our increasing demand for foods sourced from animals puts a greater burden on our natural resources
• B. Diets based on grains, nuts, fruits and vegetables are best suited for health in developing countries
• C. Human beings change their food habits from time to time irrespective of the health concerns
• D. From a global perspective, we still do not know which type of diet is best for us