Before direct proof of DNA being the genetic material,indirect evidence suggesting DNA as the appropriate macromolecule,included

A) Gametes have 1/2 the amount of DNA as somatic cells
B) Molecular composition of DNA is the same in different cells of an organism, whereas RNA and protein contents vary
C) A correlation between DNA content and the number of chromosome sets per cell
D) DNA is more stable than RNA or protein
E) All of these