Answer:
The correct anser is parenthetical expression.
Step-by-step explanation:
A parenthetical expression refers to a word or group of words added to a sentence, without changing the meaning of such sentence. In other words, a parenthetical expression gives extra but not essential information into a sentence therefore, it could be either added or removed from a particular sentence and it would not change its meaning.
Bearing in mind the stated above, it could be said that a clause or phrase that is inserted into the flow of the text and does not directly deal with the current topic is called a parenthetical expression.