The rare earth elements include A. the lanthanide series and the alkali metals. B. the alkali metals and the transition metals. C. the actinide series and the alkaline earth metals. D. the lanthanide series and the actinide series

The rare earth elements include the lanthanide series, scandium and yttrium. They are a set of seventeen chemical elements in the periodic table. They really are not that rare but they occur together in nature and are hard to separate from one another.

D. The Lanthanide Series and the Actinide series.