The early experiments that identified DNA as the hereditary molecule were not about inheritance at all. Instead, Frederick Griffith, Oswald Avery, and other scientists were studying how one Streptococcus pneumoniae strain transfers its traits to another strain through a process called

Transformation

Explanation:

The experiments which later helped in identifying DNA as the genetic material was not performed to identify the genetic material but to study the process which transformed the one strain to another strain.

This experiment was performed by the Frederick Griffith, when he was studying the mechanism of the death caused by Streptococcus pneumonia.He injected the dead virulent strain with live avirulent strain but it killed the mice.

This led to the conclusion that avirulent bacteria got transformed into the virulent bacteria and the process was called transformation.

This process of transformation was later studied by the Avery and other scientists to identify the molecule responsible for transformation and identified as DNA.

Thus, Transformation is the correct answer.