premise: From among ten stones, a jeweler will select six, one for each of six rings. Of the stones, three—F, G, and H—are rubies; three—J, K, and M—are sapphires; and four—W, X, Y, and Z—are topazes. The selection of stones must meet the following restrictions: At least two of the topazes are selected. If exactly two of the sapphires are selected, exactly one of the rubies is selected. If W is selected, neither H nor Z is selected. If M is selected, W is also selected. If J and M are the only sapphires selected, which one of the following could be true?
hypothesis: F and X are both selected.