What type of source was Brandon using when he contacted his college roommate for car information?

Brandon was using an external source by contacting his college roommate for car information. External sources refer to information collected from individuals or entities outside of one's personal experience or organization. In this case, the college roommate provides information that is not derived from Brandon's own knowledge or experience but rather from their own perspective or experience with cars, making it an external source of information.

On the other hand, an internal source would involve gathering information from within Brandon's personal knowledge or immediate circle, such as family members or personal experiences. A digital source typically refers to information obtained from online platforms or databases, while a hybrid source combines elements of both internal and external sources. In this scenario, since the information is being sought from a peer rather than digital channels or personal experience, it clearly aligns with the characteristics of an external source.