IF RESEARCHERS WANT TO PROVE THAT CRANBERRY JUICE CAN PREVENT URINARY TRACT INFECTION IN HUMANS,

IF RESEARCHERS WANT TO PROVE THAT CRANBERRY JUICE CAN PREVENT URINARY TRACT INFECTION IN HUMANS, THEY WOULD CONDUCT WHICH OF THE FOLLOWING TYPES OF STUDIES?HUMAN INTERVENTION STUDY, CASE STUDY, LABORATORY STUDY, HUMAN OBSERVATION STUDY