A 42-year-old man with type 2 diabetes mellitus presents for routine follow-up. His current HbA1c is 8.2% despite metformin monotherapy. The endocrinology team initiates a quality improvement project using Plan-Do-Study-Act (PDSA) cycles to reduce HbA1c in their diabetic patient population. In the first cycle, they implement a structured telephone-based coaching program focused on medication adherence and glucose self-monitoring for 30 consecutive patients over 8 weeks. At the end of this period, the team collects HbA1c measurements and gathers qualitative feedback from participants. Which step in the PDSA cycle is most critical for determining whether the intervention should be continued, modified, or abandoned?

1. A)Study phase: Analyze HbA1c changes and interview participants to understand why the intervention succeeded or failedGABARITO
2. B)Plan phase: Retrospectively review the past 5 years of HbA1c data to establish baseline improvement trends independent of the intervention
3. C)Do phase: Immediately scale the intervention across all outpatient endocrinology clinics to increase patient volume and statistical power
4. D)Act phase: Standardize the telephone coaching program hospital-wide without modification based on the small pilot group results
5. E)Control phase: Establish a matched control group of untreated diabetic patients to serve as comparison for all future PDSA cycles