Assuming that none of the following molecules contain any rings, which one contains exactly one carbon-carbon or carbon-oxygen double bond?

W) C\({}{4}\)H\({}{8}\)O

X) C\({}{4}\)H\({}{8}\)Cl\({}{2}\)

Y) C\({}{4}\)H\({}{4}\)O

Z) C\({}{4}\)H\({}{4}\)Cl\({}{2}\)
W) C\({}{4}\)H\({}{8}\)O