To solve this problem, we need to identify the experiment that provided the final proof for DNA as the genetic material. Let's analyze the contributions of each option:$\newline \bullet$Hershey and Chase:$\newline$ - In 1952, Alfred Hershey and Martha Chase conducted experiments using bacteriophages (viruses that infect bacteria) to demonstrate that DNA is the genetic material.$\newline$ - They used radioactive isotopes to label DNA and proteins separately in the phages.$\newline$ - After allowing the phages to infect bacteria, they found that only the DNA entered the bacterial cells, while the protein coat remained outside.$\newline$ - This experiment provided conclusive evidence that DNA is the genetic material.$\newline \bullet$Avery, Mcleod, and McCarty:$\newline$ - In 1944, they demonstrated that DNA is the substance that causes bacterial transformation.$\newline$ - Their work was crucial but not universally accepted as the final proof at the time.$\newline \bullet$Hargobind Khorana:$\newline$ - He is known for his work on the genetic code and protein synthesis, not directly related to proving DNA as the genetic material.$\newline \bullet$Griffith:$\newline$ - In 1928, Frederick Griffith discovered the phenomenon of transformation in bacteria, which laid the groundwork for identifying DNA as the genetic material.$\newline$ - However, his experiments did not identify DNA as the transforming principle.$\newline$Based on this analysis, the final proof for DNA as the genetic material came from the experiments of Hershey and Chase.$\newline$Therefore, the correct option is Option 1: Hershey and Chase.