Mr. and Mrs. VanDaan joined Anne Frank and her family while they are in hiding. Therefore, they could not have protected them and brought them food since they are hiding too. Margot is Anne's sister so she was also in hiding. This leaves the only option as option A, Miep and Mr. Kraler. They were people that Mr. Frank trusted with their secret. Miep and Bep actually found Anne Frank's diary and kept them safe.
