Alright, so hydrogen bonding usually happens when hydrogen is attached to a very electronegative atom like oxygen, nitrogen, or fluorine — and then it interacts with another electronegative atom nearby. That’s why water (H₂O), glycerol, and HF show strong hydrogen bonding.  

If you look at H₂S though… sulfur isn’t as electronegative as oxygen or fluorine, so the attraction isn’t strong enough for significant hydrogen bonding.  

So, thinking about that, which one do you suspect might not form strong hydrogen bonds?