Answer:
A. She loved him
Explanation:
Mrs. Linde and Krogstad once had a romantic relationship. But Mrs. Linde left Krogstad to marry Mr. Linde because he was wealthy and could cater for Mrs Linde's mother and brothers. Another reason she left Krogstad for Mr. Linde was because Krogstad wasn't ready and didn't have money.
Mrs. Linde still loved Krogstad and wanted to really see him. But she knew that she was married already to Mr. Linde.