Mark the letter A, B, C or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions
Expert thought that infected chickens were responsible for the outbreak of flu.
A. It is thought that infected chickens were responsible for the outbreak of flu
B. Infected chickens were thought to be in charge with the outbreak of flu
C. Infected chickens were thought to be in charge of the outbreak of flu
D. Infected chickens are thought to be responsible for the outbreak of flu.