Which of the following best describes why invertebrates isn't considered a scientifically valid word when classifying animals? a. the term invertebrates describes all animals, so is not in classifying organisms within the animal kingdom. b. the term invertebrates is because all animals possess some sort of backbone or notochord. c. the term invertebrates classifies animals haphazardly based on a missing characteristic rather than a common one. d. the term invertebrates is too vague, since all animals evolved from single-celled organisms without a backbone.

Option C

Explanation:

In general vertebrates are organism that has backbone/spine or a vertebral column derived from notochord. While invertebrates are organism that do not have any backbone or vertebra column.  

All classification terminologies categorize animals or plants on the basis of some common characteristics. However, in the case of this word invertebrate there is no categorization on the basis of common characteristics, it simply distinguish animals from each other on the basis of presence of backbone/spine/notochord.  

Hence, option C is correct

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.

wegner's theory did not explain how the continents could move

explanation: