Frederick Griffith heat-killed a culture of pathogenic bacteria. He split the sample and injected half of it into mice. The mice lived. He then mixed the other half with a living, nonpathogenic bacteria strain and injected the mixture into mice. The mice died. These results best support which of the following conclusions.
A) the initial heat treatment was unsuccessful B) splitting the culture revived the pathogenic bacteria C) non-pathogenic bacteria were transformed by pathogenic capsule proteins D) a substance had been transferred from pathogenic to nonpathogenic bacteria