Lin works for the U$.$S$.$ military in a Sensitive Compartmented Information Facility

$($SCIF$).$ SCIF security prevents outside surveillance, enabling people to view and discuss sensitive information. Lin's job is to design the strongest security possible to protect the facility. Which of the following is the strongest combination of authentication for entering the facility?

A$.$ A fingerprint scan and entering a code from a token

B$.$ A hand $($palm$)$ scan and entering a code from a token

C$.$ Swiping an ID badge and voice recognition

D$.$ A retinal scan, swiping an ID badge, and typing in a PIN