The answer is B. The values of y must only be positive because it is equal to The other options states that the values of y could be negative which is why it is wrong.
There are 3 bracelets. The first bracelet can occupy a position in 3 ways. The second bracelet can occupy the remaining 2 positions in 2 ways. The third bracelet can occupy the remaining position in 1 way. The total number combinations is 3*2*1 = 6