During Griffith's experiments with Streptococcus pneumoniae in mice, material from __________ bacteria transformed __________ bacteria.

• A. living nonpathogenic; living pathogenic
• B. living nonpathogenic; heat-killed pathogenic
• C. living pathogenic; heat-killed nonpathogenic
• D. heat-killed nonpathogenic; living pathogenic
• E. heat-killed pathogenic; living nonpathogenic