The $\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ is a formalized group$/$team decision$-$making technique that is usually conducted through the use of e$-$mail or snail$-$mail questionnaires by a researcher or analysist without any face$-$to$-$face contact between the various knowledgeable persons or experts being examined.

Question $23$ options:

A$.$ Nominal Group Technique $($NGT$)$

B$.$ Oracle Solicitation $($OS$)$

C$.$ Delphi Method

D$.$ All$-$Channel Network