The answer is B. un cuaderno
Luego explica sus el contexto del artículo
It's asking what is the theme of the story, the message the author is trying to convey, in five complete sentences. You can word it like this:
El mensaje que el autor trata de expresar es ...
Which translates to:
The message the author is trying to convey is ...
Yo tengo un amigo.
Nosotros somos altos.
