Through thorough investigation, Dr. John Snow was finally able to prove that the outbreak of Cholera _____ people’s drinking of polluted water

1. A.
   was close linked with
2. B.
   closely linked to
3. C.
   was close connected with
4. D.
   was closely linked with

Through thorough investigation, Dr. John Snow was finally able to prove that the outbreak of Cholera _____ people’s drinking of polluted water.

Through thorough investigation, Dr. John Snow was finally able to prove that the outbreak of Cholera _____ people’s drinking of polluted water.

　 A. was close linked with B. closely linked to C. was close connected with D. was closely linked with