(B) is the only option where the scientific method can be used meaningfully.
The scientific method involves an experiment to answer a question. The outcome of a valid experiment needs to be reproducible. In the case of health and consumption of meat, this could be a study evaluating eating patterns and participants' health metrics. The outcome would be measured as some kind of correlation, and even causation, making a statistical statement about how meat does or does not play role in our health.
A and D are personal choices, not something decidable by science. C is a matter of opinion, and perhaps collective decision. None of these are reproducible in different contexts.