Why did German nationalists like Otto von Bismarck support the colonial ideas of Carl Peters and others?

The correct answer to this open question is the following.

Although there are no options attached, we can say the following.

German nationalists like Otto von Bismarck support the colonial ideas of Carl Peters and others because he agreed with them in that the many different German tribes needed unification.

Carl Peters was the German politician that supported the idea of having a German unification through a league in which many German organizations could participate.

So Bismark followed through in this nationalistic idea and could unify Germany in 1871 and became its first chancellor. He ruled the unified state until 1890.

i believe your answer is d)