which of the following technologies is the most affective?

In terms of the order of effectiveness, which of the following technologies is the most affective?

A.
Fingerprint

B.
Iris scan

C.
Keystroke pattern

D.
Retina scan

Explanation:
The order of effectiveness has not changed for a few years. It is still the same today
as it was three years ago. The list below present them from most effective to list
effective:

Iris scan
Retina scan
Fingerprint
Hand geometry
Voice pattern
Keystroke pattern
Signature