I believe the answer is B.
Autotrophs are also called producers. They produce food not only for themselves but for all other living things as well.
the answer to your question is stressful
Look over each of the choices, and plug in each answer to see which one makes more sense, or rather, adds understanding to what you are reading. Start from the bottom. Adding 'and' does little in the way of allowing the reader to understand better. The same can be said for explaining what a tax burden is. By stating the 'therefore', you are saying that what comes after is a factual statement. Adding 'however' is the only answer that improves the relationship between the two ideas.
