Hydrogen bonds between water molecules are than covalent bonds.

Weaker

Explanation:

Without any other context, i'm going to assume that this is comparing the strength of Van der Waals force and covalent bonds.

Van der Waals forces are inter-molecular forces generated because of the polar nature of the water molecule. These are weaker than intra-molecular covalent bonds (which involve sharing of electrons)

b would be the right answer

if you know your abc's you should be able to get your answer or just use google