Is there any choices for this question?
Incorrect the correct one is “El panadero TUVO que hacer pan en la noche”
Haya existido is the correct answer. so you're right it's B
I'm pretty sure you would put "Leo" in the blank space because the verb "leer" means to read and the sentence prior to the blank space says "the magazine 'Cosas (or Things)' is my favorite. I read it every month. Hope this helps!