Mrs. Pearson's family had been unappreciative towards her.

Explanation:
- Unappreciative refers to a lack of gratitude or recognition for someone's efforts or qualities.
- In this context, it means that Mrs. Pearson's family did not show or express appreciation for her.
- This could imply that they did not acknowledge her hard work, support, or sacrifices for the family.
- It suggests a lack of gratitude or thankfulness for her contributions and presence in their lives.

Why the other options are not correct:
a) Respectful: Respectful means showing admiration and consideration for someone. It implies that Mrs. Pearson's family treated her with respect, which contradicts the given information that they were unappreciative.
b) Polite: Polite refers to behaving in a courteous and respectful manner. If Mrs. Pearson's family were polite towards her, they would have shown basic manners and consideration, which is contradictory to being unappreciative.
c) Biased: Biased means having a preference or prejudice for or against someone or something. It does not fit in the context of the question as it does not convey any specific behavior towards Mrs. Pearson.
d) Unappreciative: This is the correct answer as it accurately describes the family's attitude towards Mrs. Pearson - a lack of appreciation or gratitude for her.

In conclusion, Mrs. Pearson's family had been unappreciative towards her, which suggests they did not show gratitude or recognition for her efforts and contributions.