An index fossil must be A. unique in its appearance. B. smaller than other fossils around it. C. larger than other fossils around it. D. older than 1 billion years.

A.

Explanation:

Index fossils should be easily identifiable in appearance, and also geographically widespread so we can use them to "time-match" them to layers of earth that were formed around the same time, but separated at huge differences.

They kinda serve as mother nature's timestamps, so it makes sense that you want them to be easy to tell apart from other fossils from other time periods.

affirmative action refers to the policies that take gender, race, or ethnicity into account in order to promote equal opportunity.

employers subject to title vii are prohibited from taking race or sex into account in any employment decisions. aa is a penalty for having any job group substantially statistically "underutilized" in any race or either sex. the employer must take steps to eliminate the underutilization, then stop, ending its aa efforts