The security manager of a company has hired an external consultant to conduct a security
assessment of the company network. The contract stipulates that the consultant is not allowed to
transmit any data on the company network while performing wired and wireless security
assessments. Which of the following technical means can the consultant use to determine the
manufacturer and likely operating system of the company wireless and wired network devices, as
well as the computers connected to the company network?

A.
Social engineering

B.
Protocol analyzer

C.
Port scanner

D.
Grey box testing