Be/ doctor/ she/ know/ what/ side-effects/ medicine/ have//

• A. 
  Be a doctor, she knows what side-effects the medicine can have.
• B. 
  Being a doctor, she knew what side-effects the medicine could have.
• C. 
  Having been a doctor, she had known what side-effects the medicine could have.
• D. 
  To be a doctor, she knows what side-effects the medicine might have.