A Preferred and Highly Accurate Method of Diagnosing Hypertrophic Pyloric

A preferred and highly accurate method of diagnosing hypertrophic pyloric stenosis is:

A) ultrasonography with delay in gastric emptying and one or two narrow pyloric channels
B) upper gastrointestinal series with delay in gastric emptying and one or two narrow pyloric channels.
C) passing a lighted tube from the mouth into the stomach
D) doing a pH test on the stomach contents collected over a 48-hour period