Answer:
A. Mysterious
Step-by-step explanation:
In literature, the term tone refers to the mood created by the author's word choice and the way that the text makes the reader feel.
The tone of the given excerpt is mysterious. Described events begin in darkness, which means that the house is not completely visible. There are some things the narrator can make out, though. The shutter of one window is ajar, giving hints of what is inside. The characters look at what is going on in there through the window, seeing a young woman singing a lullaby while attending to a large black pot. We don't know who the woman is, what she is doing exactly, or what's in the pot. Everything is somewhat mysterious, and we want to find out more.