The correct answer is option 'B', cognitive domain.

Explanation:
The cognitive domain refers to the mental processes and thinking skills involved in acquiring knowledge and understanding. When teaching Social Studies, conceptualization is an important objective within the cognitive domain. Here's a detailed explanation of why conceptualization is important in teaching Social Studies:

1. Understanding complex concepts: Social Studies covers a wide range of topics such as history, geography, civics, and economics. These subjects involve complex concepts that students need to understand. Conceptualization helps students grasp abstract ideas and develop a deep understanding of the subject matter.

2. Making connections: Social Studies is an interdisciplinary subject that explores the relationships between various aspects of human society. Through conceptualization, students can make connections between different concepts, events, and ideas. This allows them to see the bigger picture and understand how various factors influence each other.

3. Critical thinking: Conceptualization encourages students to think critically and analyze information. It involves breaking down complex ideas into smaller components, identifying key elements, and understanding their relationships. This process develops students' analytical skills and helps them evaluate different perspectives and make informed judgments.

4. Problem-solving: Social Studies often involves studying historical events, societal issues, and global challenges. Conceptualization enables students to analyze these problems, identify possible causes and solutions, and develop strategies to address them. It fosters problem-solving skills and empowers students to become active participants in their communities.

5. Transfer of knowledge: Conceptualization helps students transfer their knowledge and skills to new situations. By understanding the underlying concepts, students can apply their learning to real-world scenarios and make connections between different contexts. This enhances their ability to use Social Studies knowledge in practical and meaningful ways.

In conclusion, conceptualization is an important objective of teaching Social Studies under the cognitive domain. It supports students in understanding complex concepts, making connections, developing critical thinking and problem-solving skills, and transferring their knowledge to real-world situations.