**Core Concept**
The determination of the sequence of a polypeptide is a crucial aspect of biochemistry, involving the identification of the order of amino acids in a protein. This process is essential for understanding protein structure and function, as well as for the development of new therapeutic agents.

**Why the Correct Answer is Right**
Frederick Sanger was a British biochemist who made significant contributions to the field of biochemistry, including the determination of the sequence of a polypeptide. In 1955, Sanger was awarded the Nobel Prize in Chemistry for his work on the structure of proteins, specifically insulin. He developed a method for sequencing proteins, which involved the use of chromatography and chemical reactions to identify the individual amino acids. Sanger's work laid the foundation for modern protein sequencing techniques.

**Why Each Wrong Option is Incorrect**
**Option A:** Pehr Edman was a Swedish biochemist who developed a method for sequencing proteins, known as Edman degradation, but he was not the first to determine the sequence of a polypeptide.

**Option C:** John Kendrew was a British biophysicist who determined the structure of myoglobin, a protein found in muscle tissue, using X-ray crystallography. While Kendrew's work was significant, it was not related to the sequencing of a polypeptide.

**Option D:** There is no notable biochemist by the name of Oakley Fulthrop, making this option an obvious incorrect choice.

**Clinical Pearl / High-Yield Fact**
Frederick Sanger's work on protein sequencing has had a lasting impact on the field of biochemistry, and his method remains a fundamental tool for understanding protein structure and function.

**✓ Correct Answer: B. Frederick Sanger**