Question

which best describes eras and periods? eras have a smaller time span than periods. eras and periods are independent of each other. eras and periods both appear at the start of the cambrian period. eras were more recently established on the time scale than periods.

Explanation:

In geological time - scale, eras are larger - scale divisions than periods. They are not independent as periods are sub - divisions within eras. They didn't both start at the Cambrian period and eras are not more recently established than periods.

Answer:

None of the above options are correct.