Why do water molecules tend to stick to each other to form a liquid?

Question

1. The hydrogen atoms form negative ions that can make ionic bonds with oxygen.
2. The exposed charge on hydrogen's protons are attracted to unshared electron pairs on oxygen atoms. 
3. Water molecules can share electrons with neighboring molecules forming strong covalent bonds.

which of the option ?

Answer 1

1. The exposed charge on hydrogen's protons are attracted to unshared electron pairs on oxygen atoms. 

This called hydrogen bonding and is seen with compounds where hydrogen is bound to nitrogen, oxygen, and fluorine.

N-H ····N O-H·····O F-H····F the dots are the hydrogen bonds to N, O, and F.

It can also be N-H····O O-H····N etc.