it helps the plant develop healthier
Answer: multi-cellular bodies
Explanation: All animals are multi-cellular. This means that they are made up of many cells/cellular systems. Single-celled organisms, on the other hand, are not considered animals. Those would mostly be too tiny to see without the aid of a microscope tool. The other answer choices would not fit, because not all animals have bones (endoskeletons or exoskeletons). Also, only some animals are cold blooded, which is what the last answer choice has to do with.
Answer:
A. When oxygen levels within a cell are too low for aerobic respiration
Explanation:
Fermentation is a chemical or metabolic process that occurs in organism, when a carbohydrate such as glucose is metabolized or converted to an alcohol anaerobically (absence of oxygen).
When an organism lacks oxygen within the cell, aerobic respiration would be halted, hence pyruvate produced from glucose further undergoes fermentation anaerobically.
Organisms like lactic acid bacteria and yeast carry out fermentation. The process of fermentation is widely used in food industries, such as in brewing of wine or manufacture of yogurt.
I would say D. natrural selection