The strongest evidence that $DNA$ is genetic material comes from

$DNA$ was first discovered by

Analyze the following experimental steps performed by Frederick Griffith:
$I - R$ strain $\rightarrow$ injected into mice
$II - S$ strain $\rightarrow$ injected into mice
$III - S$ strain (heat-killed) $\rightarrow$ injected into mice
$IV - S$ strain (heat-killed) $+ R$ strain (live) $\rightarrow$ injected into mice
In which of the above stages will the mice remain alive?

Who proved that $DNA$ is the genetic material?

Who revealed the biochemical nature of the transforming principle? How was it done?

Write a short note on the biochemical characterization of the Transforming Principle.