A 2-week-old female is brought to the office for a well child visit. The physical examination is completely normal except for a clunking sensation and feeling of movement when adducting the hip and applying posterior pressure. Which one of the following would be the most appropriate next step? A. Referral for orthopedic consultation
B. Reassurance that the problem resolves spontaneously in 90% of cases, and follow-up in 2 weeks
C. Triple diapering and follow-up in 2 weeks
D. A radiograph of the pelvis