The details of the path of carbon in the dark reaction of photosynthesis were discovered by Melvin Calvin and his colleagues at:

Explanation

The correct answer is the University of California, where Melvin Calvin and his colleagues elucidated the path of carbon in the dark reaction of photosynthesis. This significant breakthrough in understanding the biochemical processes of photosynthesis led to Calvin being awarded the Nobel Prize in Chemistry in 1961. The other options, including Oxford University, Cambridge University, and Tubingen University, were not involved in this particular discovery.