3. The island of Rum in Scotland had wolves and trees 500 years ago. It now has neither. a. Offer one hypothesis for the current condition based on the concepts of keystone species and
trophic cascades. b. Suggest one way to test the hypothesis.

where are the choice options?

intermolecular forces are the forces between molecules or particles.

there are two kinds of van der waals forces: weak london dispersion forces and stronger dipole-dipole forces.

in molecule of water there are dipole-dipole forces between negatively charged oxygen from one molecule of water and positively charger hydrogen of another molecule of water.

hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (h), covalently bound to a highly electronegative atom such as flourine (f), oxygen (o) and nitrogen (n) atoms.  

∠gdh and ∠edh on edg.

answer is c