Introduction:
In this question, we are asked to identify what we call our parents' parents. The correct answer is option 'A', which is "Grandparents". Let's explore this in detail.

Explanation:
Definition: Grandparents are the parents of a person's father or mother. They are one generation above the parents and two generations above the person themselves. Grandparents play an important role in a person's life and often have a special bond with their grandchildren.

Roles and Relationships: Grandparents hold a significant place in the family structure and have different roles and relationships. Here are a few examples:

1. Maternal Grandparents: These are the parents of a person's mother. For example, if a person's mother's name is Sarah, her parents would be called "Sarah's parents" or "maternal grandparents".

2. Paternal Grandparents: These are the parents of a person's father. For instance, if a person's father's name is John, his parents would be referred to as "John's parents" or "paternal grandparents".

3. Relationship with Grandchildren: Grandparents often have a loving and nurturing relationship with their grandchildren. They provide guidance, support, and love to their grandchildren, creating a strong family bond.

4. Nicknames: In many families, grandparents have special nicknames given by their grandchildren. For example, "Nana" or "Grandpa" are common nicknames used to address grandparents.

Conclusion:
In conclusion, we call our parents' parents "Grandparents". They are an integral part of the family and play a significant role in the lives of their grandchildren. The bond between grandparents and grandchildren is special and cherished.