Two boys, ages 3 and 4, are playing with cars, and both boys want the bigger red car. As one boy reaches for the red car, the other strikes him, knocking it out of his hand, and taking the red car for himself. This is an example of aggression.

instrumental aggression.              

Explanation:

Instrumental aggression: In psychology, the term "instrumental aggression" is described as a person's aggressive behavior that is being intended or planned to achieve a particular goal. Instrumental aggression is being developed against the other person as a medium to whom an individual's aggression is being utilized in order to get a few rewards or to get some external goal or desire including a victory. Instrumental aggression is supposed to be carefully planned.

In the question above, the given statement is an example of instrumental aggression.

using the bering strait was the best transportation system.