Q. In a basic ultrasonic test pattern (A scan) for contact testing, the initial pulse (assume no sweep delay is used):

• (A) Is the high indication on the extreme left side of the screen that represents the entry surface of the inspected part
• (B) Is the first pulse that occurs near the right side of the screen and represents the opposite boundary of the inspected part
• (C) Is an indication that appears and disappears during screening
• (D) Is always the second pulse from the left on the viewing screen