PCR or polymerase chain reaction was discovered by

Options

A. Jeffreys et al
B. Nakumura et al.
C. Karry Mullis
D. Lander et al.

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks who discovered the Polymerase Chain Reaction (PCR).

2. **Review the Options**: The options provided include several scientists. The goal is to determine which one is associated with the discovery of PCR.

3. **Recall Relevant Information**: The Polymerase Chain Reaction was discovered by Carey Mullis, an American biochemist. He was awarded the Nobel Prize in Chemistry in 1993 for this invention, sharing the prize with Michael Smith.

4. **Confirm the Correct Answer**: Based on the information recalled, the correct answer is option number three: Carey Mullis.

5. **Discuss the Significance**: PCR is a crucial technique in molecular biology, widely used for amplifying DNA sequences, which has numerous applications, including in recombinant DNA technology.

6. **Eliminate Incorrect Options**: The other options (Jeffrey et al, Nakamura, and Lender et al) are not associated with the discovery of PCR, confirming that option three is indeed the correct choice.