Answer:
The correct answer is <u>B</u>: nonessential adjective clause.
Explanation:
Adjective clauses are dependent clauses that provide us more information about a noun or pronoun in a sentence, by acting as an adjective in that sentence. Adjective clauses can be essential and nonessential.
Essential adjective clauses contain some important details about the sentence, so they cannot be removed from the sentence, as the sentence wouldn't make sense without it.
On the other hand, nonessential adjective clauses contain nonessential information, so they can be removed from the sentence without changing its meaning. These types of clauses are separated by commas.
By saying that, he indicates that they know each other very well and that without talking, they have similar ideas and outlooks on the world in response to certain situations.
