Final answer:
Option b. summarization is correct. Effective information must be relevant, complete, and structured, while summarization is not a defining characteristic of effectiveness since it may omit important details.
Step-by-step explanation:
Effective information typically includes several key characteristics to ensure that it serves its intended purpose. These characteristics are relevance, completeness, structure, and accurate data among others.
The characteristic that is not necessarily a part of effective information is summarization. While summarization can be helpful in certain contexts to provide an overview or synthesis of information, it is not a defining feature of all effective information, which must be complete and detailed where necessary.
Considering the whole list, option 'c' summarization, is the characteristic that is not essential for information to be effective. Effective information must be relevant to the topic at hand, complete in its coverage of necessary details, and structured in a logical, understandable manner.
Summarization might simplify the information, which can sometimes lead to omissions of important details.
Hence, while summarization can be a useful tool for presenting information, it is not a characteristic that defines the effectiveness of information.
Therefore, option b. summarization is correct.