That's amazing. I'm thinking that the PSYCHOLOGIST who came up with this test may be (or may have been) a little PSYCHO himself. I pondered over this before reading the responses and MY guess was no where NEAR the correct answer. I thought that maybe the woman killed her sister because she was in love with the sister's husband or boyfriend or something along those lines.
GOSH, I'm glad to see that, while I may be SOME things (a little obsessive-compulsive, argumentative at times, and HEY, even a little SLOW when it comes to certain jokes), but, BY GOLLY, PSYCHOTIC I'm not!