Read the following advertisement and mark the letter A, B, C or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 1 to 6.

Dirty body - healthy body
Do you like to be clean? An (1) _______ thinks it could be making you sick. "Bathing removes our natural protection (2) _______ germs," said Dr. Giancarlo Pagnozzi. "Nature gives us protection, but we keep (3) _______ it away."
For seven years, researchers studied 300 people. One half (4) _______ a bath or shower every day using soap. The other half washed once a week in plain water. The super-clean team had several minor illnesses, (5) _______ 876 colds, 167 cases of flu, 49 sore throats, and (6) _______ skin diseases. The dirty group had only 29 colds, 3 cases of mild flu, and 1 sore throat - but no friends.