Select the PICO Component That Is Either Missing or Incomplete

Select the PICO component that is either missing or incomplete from this question: For a client with attachment and bone loss due to periodontal disease, will antimicrobial therapy (minocycline HCI) with scaling and root planning, as compared to antimicrobial therapy alone, be more effective?

A) P (present and complete: client with attachment and bone loss due to periodontal disease)
B) I (present and complete: antimicrobial therapy [minocycline HCI] with scaling and root planning)
C) C (present and complete: antimicrobial therapy alone)
D) O (incomplete, more effective in doing what should be specified [e.g., more effective in stopping the progression of attachment loss])
E) No component is missing/incomplete