Who is the only scientist in the world to have won the Nobel prize in Chemistry twice?

Frederick Sanger

The correct answer is Option (4) - Frederick Sanger

Frederick Sanger is the only scientist in the world to have won the Nobel Prize in Chemistry twice. He was awarded the Nobel Prize in Chemistry in 1958 for his work on the structure of proteins, particularly insulin. Sanger received his second Nobel Prize in Chemistry in 1980 for his development of methods for DNA sequencing. His groundbreaking contributions to biochemistry and molecular biology have had a profound impact on scientific research, earning him this rare distinction in Nobel Prize history.