Read the sentence from the section "The Active, Changing Layer."
Its name comes from the fact that gases in these layers are excited by solar radiation to form
ions," which have an electrical charge.
What does the word "excited" convey in the sentence?
(A)
It conveys a sense of being agitated.
It conveys a sense of being energized.
It conveys a sense of being awakened.
It conveys a sense of being enticed.
(B)
(C)
(D)