The gulf stream is a surface current in the atlantic ocean that flows northward from the caribbean sea and the gulf of mexico it feeds another current that reaches northern europe which of these events would cause the greatest changes to the path and strength of the gulf stream?

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.