What is not part of statutory social insurance?

EDITORIAL LEARNING AID

Why is this answer correct?

Statutory social insurance comprises health, pension, unemployment, long-term care and accident insurance. Life insurance (a) is private provision and not a statutory compulsory insurance, whereas pension (b), unemployment (c) and long-term care insurance (d) are part of it.

Statutory: health, pension, unemployment, care and accident, not life.

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