The SH2 domain of STAT proteins plays a key role in cytokine receptor signaling. This domain can bind to phosphotyrosine ...

A) on an activated receptor molecule, or (intramolecularly) on the same STAT molecule.
B) on a Janus kinase molecule, or (intramolecularly) on the same STAT molecule.
C) on an activated receptor molecule, or on another STAT molecule in a dimer.
D) on a Janus kinase molecule, or on another STAT molecule in a dimer.
E) on the same STAT molecule or on another STAT molecule in a dimer.