Question

Which of these best demonstrates mutualism between certain types of bacteria and humans? A Intestinal bacteria obtain nutrients from the gut and produce vitamin K used by humans. B Bacteria become resistant to antibacterial medication that humans use for treatment. Invasive bacteria at an area of injury produce toxins that damage healthy tissues of the human body. D Bacteria in improperly prepared food is consumed by humans, causing food poisoning.​

Answer 1

it will be A because they are both talking about how they are both getting help from the thing in exchange for something. It might be a little confusing at first but if you keep going through and eliminating answers that will be your only answer left