Explanation:

Temin and Baltimore discovered reverse transcriptase or RNA dependent DNA polymerase at the same time but independently of each other. For their discovery of the viral enzyme reverse transcriptase, Howard Temin and David Baltimore shared the 1975 Nobel Prize for Physiology or Medicine. Temin discovered reverse transcriptase in Rous sarcoma virus. Baltimore arrived at the same discovery through his studies on replication of RNA containing viruses starting with poliovirus and then moving to vesicular stomatitis virus where he discovered a virion RNA polymerase. 
So, the correct answer is 'Temin and Baltimore'.