The image below shows a type of human tissue.

Muscle tissue is shown.

What is its main function?

A binding organs and tissues together

B control and coordination

C movement

D protection

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.