Which of the following identifiers could be used for official business when sending a SOQ?

The use of an individual's name and date of birth as identifiers for official business, such as sending a Statement of Qualifications (SOQ), is appropriate because these pieces of information are generally recognized as uniquely identifying a person. The combination of name and date of birth is less likely to have duplicates, making it reliable for official documentation where personal identification is essential.

In contrast, the other options provided may lack the specificity or security necessary for official business. For example, a Twitter handle is not a formal identifier and could represent multiple users or change over time, making it inappropriate for official documents. Similarly, while a company ID number can be useful for identifying organizations, it would not typically apply to an individual’s qualifications. Lastly, a ZIP code can identify a general area or residence but is too broad to serve as a unique identifier for individuals in an official context. Thus, name and date of birth serve as reliable identifiers in formal procedures such as submitting an SOQ.