A.) Run On. (These are two complete sentences.)
Answer:
The apartment itself is described as being small, "a small living-room, a small dining-room, a small bedroom, and a bath," and yet everything in this small apartment is described as being large: "tapestried furniture entirely too large" for the space and an "over-enlarged photograph" of a hen sitting atop a rock.
Explanation:
This is math, not English, but okay xD
"Two intersecting lines are perpendicular if and only if they form four 90 degree angles" would be my answer.