Problem 1: DNA, the genetic material

Correct!

A	Avery, MacLeod, and McCarty who repeated the transformation experiments of Griffith, and chemically characterized the transforming principle. Avery, MacLeod, and McCarty showed that DNA from the virulent smooth strain of pneumococcus would transform rough into the smooth strain. This was the first experiment to conclude that DNA is the genetic material.
B	Garrod, who postulated that Alcaptonuria, or black urine disease, was due to a defective enzyme.
C	Beadle and Tatum, who used a mutational and biochemical analysis of the bread mold Neurospora to establish a direct link between genes and enzymes.
D	Meselson and Stahl who showed that DNA is replicated semiconservatively.
E	Watson and Crick who gave a model for the structure of DNA.