What is a custom at Easter in Germany?

EDITORIAL LEARNING AID

Why is this answer correct?

Easter in Germany includes painted eggs and hiding and searching for Easter eggs. Pumpkins in front of the door (a) are a Halloween custom, a decorated fir tree (b) belongs to Christmas, and rockets (d) are fired at New Year's Eve.

Easter: paint and hide eggs; pumpkins are Halloween.

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