It / take / two hours / go / Ho Chi Minh City / air.

• A. 
  It takes two hours going to HCMC by air.
• B. 
  It takes two hours to go to HCMC by air.
• C. 
  It takes two hours to going to HCMC by air.
• D. 
  It takes two hours go to HCMC by air.