Which is a compound-complex sentence? a) after the massacre occurred, the government started an investigation, but no one expected to find anything. b) although it will set you back at least a thousand dollars, a trip to las vegas is unforgettable. c) the funeral will be held in chattanooga, tennessee on wednesday at 10: 30 a. m. d) at six o'clock in the morning, her ceiling fan crashed to the floor.