To Display Vividly the Cause of Some Types of Ulcers

Multiple Choice

To display vividly the cause of some types of ulcers, a researcher

A) cured the patient with milk and a bland diet
B) injected himself with the bacteria from a patient's ulcer
C) injected a patient with ulcers with an antibiotic
D) injected a patient without ulcers with bacteria from a patient's ulcer