She has already been arrested by the Nazis.
Option-b.
This option is the closest to being correct.
Explanation :
Miep was a good lady who gave shelter to Anne Frank and her family and four other Dutch people who were hiding from the Nazis. Miep along with her husband took great risk of providing shelter to them as she had seen loads of Jews taken mercilessly to the concentration camps to be either killed in gas chambers brutally or to make them slaves doing hard labour.
She took great pains to provide basic necessities to the hidden ones along with her husband. On a tip off, the police came to know about the hide.
It was a working day for Miep when a man came to her working place and pointed a gun at her. Apparently, he had come to know of her identity and the fact that they were hiding the Jews.
It was after that that Anne and her family and other Jews in hiding were arrested and taken to concentration camps. She had her husband later lived in Amsterdam.