What is the basis of Germany's special responsibility for Israel?

EDITORIAL LEARNING AID

Why is this answer correct?

Germany's special responsibility for Israel arises from the National Socialist crimes against Jews, the Holocaust; from this follows the obligation to protect Jewish life and to stand up for Israel's security. Answer b is therefore correct. EU membership (a), the Basic Law (c) and the Christian tradition (d) do not establish this responsibility.

Responsibility for Israel: from the Nazi crimes against Jews.

This translation and explanation are editorial learning aids. The official German wording and answer key govern the examination.