If twitter were to exclusively use e-mail, collaborative computing, and other computer connections to connect geographically separate employees, it would be considered a(n) organization.

Virtual is the correct answer for the above question.

Explanation:

A Virtual organization is a collection which is used to connect the geographical people, organizational units, employees, individuals and groups for some communication purpose. Virtual means that there is some existence like physically but it is not physically present. So the organization also connects the person and gives the real scenario with the help of some software for communication.

The question states that if twitter uses email and other computing connections to connect people globally then it comes in the Virtual department because it follows the concept of the virtual department. Hence Virtual is the correct answer.