I am not sure I understand your multiple choices for answers, but the correct words to put into your sentence are: 'explains', and 'is'. Because the word 'either' has been used, that changes the the word after lantern from multiple to singular.
I believe the answer is : “ c . all of these “ !
Answer:
It's using more than one medium of expression or even communication.
Explanation:
The indirect clause states something that is not well know
