Your teacher wants the students to write on the board.
a) hagan l tarea b) cierren los libros c) esriban en la pizarra d) tomen apuntes

C) escriban en la pizarra

Explanation: C is correct because escriban is from the word to write, the -an at the end of it tells you that it's the students she's talking to. And la pizarra means board. Hope this helped!

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