What can limestone deposits tell scientists about the environment in which they evolved?

The formation of limestone takes place in shallow warm marine waters. Limestone forms from the collection of waste like shells, fecal matter, coral, and algal—so tropical marine animals. Since limestone is a sedimentary rock formed from tropical marine animal's leftovers, limestone deposits can tell scientists that the environment in which they evolved from was a tropical one.

answer; /// i believe the correct answer is (reactants);

the median of the data is 4.5.