Which statement about the Cambrian period is true?

Question

Quizplus · Accepted Answer

The Cambrian period is known for the Cambrian explosion, a time when many types of multicellular life forms rapidly evolved. Most of these life forms were aquatic, as the oceans were the primary habitats for life during this time. The first multicellular life appeared earlier, the Cambrian does not mark the end of the Paleozoic era but rather its beginning, oxygen concentrations were not extremely low, and large land mammals evolved much later.

Which Statement About the Cambrian Period Is True