Which of the phrases given below each sentence should replace the phrase printed in bold type to make the sentence grammatically correct?
In addition $to \,enhancing\, their\, reputations$ through strategic use of philanthropy, companies are sponsoring social initiatives to open new markets.

• A
  of enhancing their reputation
• B
  to having enhance their reputation
• C
  to enhancing their reputation
• D
  to have their reputation enhancing