Answer: I would contend that the right answer is the B) The narrator knows it is already too late for Fortunato to escape.
Explanation: Just to elaborate a little on the answer, it can be added that even though he appears to show concern for Fortunato's health, Montresor, the narrator, is only faking that concern, since his plan is to end with his friend's life, who has humiliated him for so long. He knows that Fortunato is thrilled to taste the Amontillado, and by pretending that he is concerned about his health and his exposure to the harmful nitre, he is only prompting Fortunato's excitement, while progressively reducing his possiblities of escaping.
It is significant that Darry calls Ponyboy ~Little Buddy~ at the end of Chapter 11 because the previous night when Darry and Scoda came to pick Ponyboy up from the hospital, he (Ponyboy) realises that, Darry doesn't hate him, he just worries about him.
