Playing with toys at home is a common activity for many families, and it often involves different family members. While all of the options provided in the question may have family members who play together with toys at home, the correct answer is option 'C' - Brother and Sister.

Playing with toys is an important part of a child's development, as it helps them learn and explore the world around them. When siblings play together with toys, they not only have fun but also engage in various social and cognitive activities that promote their growth and development.

Here are some reasons why brothers and sisters often play together with toys at home:

1. Sibling Bonding:
- Siblings share a unique bond and often enjoy spending time together.
- Playing with toys allows them to interact, communicate, and bond with each other.
- It helps strengthen their relationship and build lifelong memories.

2. Sharing and Cooperation:
- Playing with toys teaches siblings the importance of sharing and cooperation.
- They learn to take turns, negotiate, and compromise while playing together.
- These skills are crucial for their social development and future interactions with others.

3. Imaginative Play:
- Toys provide a platform for imaginative play, where siblings can create stories, scenarios, and role-play.
- They can use their creativity and imagination to invent characters, build worlds, and engage in pretend play.
- This type of play enhances their cognitive skills, problem-solving abilities, and language development.

4. Learning from Each Other:
- Siblings of different ages often have different knowledge and skills.
- Playing together allows them to learn from each other and share their experiences.
- Older siblings can guide and teach younger ones, while younger siblings can bring fresh perspectives and ideas.

5. Emotional Support:
- Playing with toys together can also provide emotional support for siblings.
- They can comfort each other, share their feelings, and provide a sense of security during playtime.
- This emotional connection is essential for their well-being and overall development.

In conclusion, while other family members such as aunt and uncle, mother and father, or father and grandfather may also play together with toys at home, the bond between brother and sister is often the strongest, making them more likely to engage in playtime together. Playing with toys allows siblings to bond, learn important social skills, enhance their imagination, and provide emotional support to each other.