Identify the level of use of the following sentence.

necessarily, therefore, none of them has the completeness of effect which is so marked in the oresteia .

formal
general
informal
substandard

Formal.

Explanation:

Formal language consists of a vocabulary set that will not normally be used in everyday life situations, but in special occasions which requiere a serious and  professional attitude.

Regarding the example sentence, adverbs such as "Necessarily" and "Therefore" are usually used as text initiators on a formal text, rather than in friendly conversations.

a. to introduce the audience to important characters .

b. to inform the audience where the story takes place .

e. to lay out specific details about different plot points.