During analysis of static standing posture in a 16-year-old female, the physical therapist notices unilateral pronation in the right ankle as well as a slight genu valgus in the right knee. Which of the following SHOULD BE MEASURED in order to help identify the underlying cause of this postural deviation?

a) bilateral leg length to determine whether there is a leg length discrepancy
b) dorsiflexion range of motion on the right
c) hip flexor tightness on the left
d) medial collateral ligament laxity on the right