Gefitinib and Erlotinib are two drugs that effectively inhibit cell proliferation driven by oncogenic HER alleles, but unlike Cetuximab or Herceptin, they paradoxically increase the levels of these receptors on the plasma membrane. What is the mechanism of action for Gefitinib and Erlotinib?

A. Both drugs inhibit ligand binding to oncogenic HER alleles.

B. Both drugs inhibit GRB2 GEF activity

C. Both drugs inhibit SOS GEF activity

D. Both drugs inhibit AP2 binding to Clathrin

E. Both drugs inhibit oncogenic HER kinase activity