Ellos mucho sobre el arte.
a. saben
b. conocen

A. Saben

Explanation:

Conocen is like getting to know and Saben is knowledgeable                                        

in the dark you call me from the darkness you called me i recognized your voice you recognized my neighbor for here i said you where you are dad i do not see you here i am here and i am afraid you said not my son wait i have you where are you this dark i do not see anything i have fear do not be afraid, son, right now, i'm coming soon, papa, i'm waiting for you, a father cries out to his son

c. its asking which of the words need an accent mark. its spelled biografía