De Novo Purine Biosynthesis Is Distinguished from De Novo Pyrimidine

De novo purine biosynthesis is distinguished from de novo pyrimidine biosynthesis by:

A) condensation of the completed purine ring with ribose phosphate
B) incorporation of CO₂.
C) inhibition by azaserine (a glutamine analog) .
D) participation of aspartate.
E) participation of PRPP (phosphoribosyl pyrophosphate) .