Explanation:

- Har Gobind Khorana (Option 4) is the correct answer. He was awarded the Nobel Prize in Physiology or Medicine in 1968, along with Robert W. Holley and Marshall W. Nirenberg, for his research that helped crack the genetic code, revealing how sequences of nucleotides in DNA and RNA determine the amino acid sequences in proteins.

- Venkatraman Ramakrishnan (Option 1) received the Nobel Prize in Chemistry in 2009 for studies of the structure and function of the ribosome, but he did not directly contribute to the initial cracking of the genetic code.

- Abdus Salam (Option 2) was a theoretical physicist who shared the 1979 Nobel Prize in Physics for contributions to the electroweak unification theory, unrelated to genetic code research.

- Subramaniam Chandrasekar (Option 3) was awarded the 1983 Nobel Prize in Physics for theoretical studies of the physical processes important to the structure and evolution of stars.

- Thus, the correct answer is Har Gobind Khorana.