Observing a friend's success at quitting smoking has you to quit a few months later, which demonstrates the process of

modeling

Explanation:

In psychology modeling is a way to learn something by the simple act of imitation. The person is not told what to do but imitates the action of another person. The person the other person is trying to imitate is called the model.

Here, the friend is the model and you are the person who is modeling yourself to act like him i.e., you try to quit smoking just like your friend.

b) trade is easy because of the direct line between their major ports. bilateral trade reached 89,6 thousand million.