What did Billy say to the Austrian ski instructor when they found him in the mountainside (Slaughterhouse)

Austrian ski instructors wearing black ski masks arrive on the scene. As they check for signs of life, Billy whispers “Schlachthof-fünf” (“Slaughterhouse-Five” in German), a phrase he learned in Dresden in order to communicate the address of his prison if he got lost.

Explanation:

- "a nonrestrictive clause functions as a modifier to a noun (that is an object, person or concept). these clauses can be described by the following three options: it is set off by comas, it contains a subject and a verbs and it adds nonessential information to the sentence.

for example, in "here is bill gates, who confounded microsoft software company" we can identify "who confounded microsoft software company" as a nonrestrictive clause modifying the noun bill gates. this clause can be describes as a nonrestrictive clause because it is separated by a comma, it adds nonessential information to identify who bill gates is and it must contain both a subject (who) and a verb (confounded)."

i believe that the answer is b! i hope i out!