To solve this problem, we need to identify who discovered the process of transformation. Let's analyze the options:$\newline \bullet$Option 1: Meselson and Stahl - They are known for their experiment on DNA replication, demonstrating the semi-conservative model.$\newline \bullet$Option 2: Hershey and Chase - They conducted experiments that confirmed DNA as the genetic material using bacteriophages.$\newline \bullet$Option 3: Griffith - Frederick Griffith discovered the phenomenon of transformation in 1928 through his experiments with Streptococcus pneumoniae.$\newline \bullet$Option 4: Watson and Crick - They are famous for elucidating the double helix structure of DNA.$\newline$Based on this analysis, the correct answer is Option 3: Griffith, who discovered transformation.