Question: A pharmaceutical company develops a new antibiotic to treat pneumonia. After limited testing, the researchers conclude that the antibiotic seems to be effective. How can the researchers strengthen their conclusions?

  Options: 
 A. Test the antibiotic on human volunteers.
 B. Publish their results in a medical journal.
 C. Ask an independent lab to retest the antibiotic.
 D. Test the effectiveness of the antibiotic at killing other bacteria. 
Answer: C