What is invigilation?

Group of answer choices

a$.$ A theft act investigative technique that records the physical evidence, facts, and movements which form part of a fraud.

b$.$ A theft act investigative technique that involves close supervision of the suspects during the examination period.

c$.$ A theft act investigative technique that is used when large$-$scale fraud is likely and other methods of investigation fail.

d$.$ A theft act investigative technique that involves confiscating and searching computers and other electronic sources of information.