Which of the Following Events Contributes to Driving the Mammalian

Multiple Choice

Which of the following events contributes to driving the mammalian cell past the restriction point of the cell cycle?

A) Phosphorylation of Cdh1-APC/C by G₁/S-Cdk
B) Destruction of CKIs that target S-Cdks
C) Phosphorylation of Rb by G₁-Cdk, G₁/S-Cdk, and S-Cdk
D) Activation of E2F gene expression by active E2F protein
E) All of the above