Which of the following does NOT have an index of hydrogen deficiency of 3?

W) Spiropentane [spy-roh-PEN-tayn]

X) Norbornene [nohr-bohr-NEEN]

Y) 1,3-cyclohexadiene [1 comma 3-sy-kloh-HEK-suh-deen]

Z) trans-1,3,5-hexatriene [trans-1-comma-3-comma-5-hex-SUH-treen]
W) SPIROPENTANE