It's a really picky question. The ovary basically releases an ovum directly into the fallopian tube. By "body cavity" they literally mean the abdominal space of a woman, the abdominopelvic cavity. So it's easier to just remember the egg goes from the ovary to the fallopian tube. But technically, the egg is released into the body cavity, and the fimbriae on the end of the fallopian tube guide it in. It's like the tiniest, microscopic space between the two, because both structures are closely associated.
