Aditya is attempting to classify information regarding a new project that his organization will undertake in secret. which characteristic is not normally used to make these type of classification decisions?

Threat is not normally considered as a characteristic. Value of the project, the sensitivity of it, and how critical the project is to completion and maintenance are all characteristics that are considered, but since anything could likely be considered a threat to the project, it is simply understood that this characteristic is part of the secret project.