When McLeod, Avery and McCarty experimented to establish the chemical nature of the 'Transforming Principle', which of the following statement/s helped them reach their conclusion?
1: Proteases did not affect transformation
2: DNases did not affect transformation.
3: RNases did not affect transformation.
4: The R strain could synthesise the polysaccharide coat.
A. only 1 and 2
B. only 1 and 3
C. only 1, 3 and 4
D. only 2,3 and 4
