Which scanning methods could be classified as immersion type test?

Which scanning methods could be classified as immersion type test?

• A. Tank in which the search unit and test piece are immersed
• B. Squirter bubbler method in which the sound is transmitted in a column of flowing water
• C. Scanning with a wheel type search unit with the transducer inside a liquid filled tire
• D. All of the above

Answer: (D)