Foreign employees who were recruited by the Federal Republic of Germany in the 1950s and 1960s were called …

EDITORIAL LEARNING AID

Why is this answer correct?

The foreign workers recruited in the 1950s and 1960s were called guest workers; initially they were only supposed to work in Germany for a limited period. Illegal workers (a), temporary workers (c) and shift workers (d) describe other forms of employment.

Guest workers: recruited in the 1950s and 1960s.

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