According to the passage, the statement which is true is that______ .

• A. 
  the civilization of Angkor began to decline in the late 1100’s
• B. 
  most of Angkor was covered by the forest during the Thai invasion
• C. 
  invasions from Thailand was one of the causes of the Angkor decline
• D. 
  many temples in Angkor were rebuilt by French and Cambodian archeologists