Answer:
D.The parlor of the house is small, so the characters are probably desperately poor.
Step-by-step explanation:
I think this is the only only information we can infer from the sentence given. Remember that by "infer" we mean to deduce from the evidence and reasoning. Although the size of the parlor is not enough to conclude that characters are desperatly poor, it indicates that they are not wealthy enough to have a big house. It might not be enough to be conclusive but it's a justified reason.
The other options can make a reasonable inference, the facts do not relate with the conclusions.