Why is orientation important when inspecting with UT?

• A. UT results are independent of flaw orientation; orientation does not affect detection.
• B. The transducer resolution changes with orientation but detection is unaffected.
• C. Flaws often reflect energy in a way that is independent of angle, so orientation is not important.
• D. Flaws have directional reflectivity; orientation affects detectability and sizing due to beam path and reflection geometry.

Answer: (D)