If you know an index fossil existed between 20 and 15 million years ago, what can you assume about the age of the rock in which the index fossil is found?

the correct answer is option b

behavioral response need communication and thus co-ordination at several levels such as interaction among cells, organ system and the entire organism.

behavioral response produces both internal and environmental stimulus.

emerging idea only occurs as a raw idea that could appear out of nowhere. meanwhile, to reach scientific consensus , that idea must be structured and tested over and over again through various experiments. the scientific consensus transforms the raw idea into idea that is more reliable through the process of scientific elimination.

the answer is 100% density i've answered this question before and done the quiz myself.

what questions are you talking about ?