The question asks the student if they are familiar with various vocabulary words used throughout their Spanish studies. "La paz" (peace), "la amistad" (friendship), and "el acuerdo" (agreement) all fit together; however, "la guerra" (war) represents conflict and does not belong in this group.

The phrase "mi hermanito" (my little brother) cannot be used to complete this sentence because there is no presence of the personal “a.” Direct object nouns that represent people must have “a” inserted directly in front of them.