STATs are: A. Cytoplasmic transcription activators that are activated by dephosphorylation of an inactive complex B. Are activated by a tyrosine kinase complex that is found in the nucleus C. Extracellular ligands that stimulate T-cell differentiation. D. Are activated by a cytoplasmic tyrosine kinase complex that results in phosphorylation and dimerization of the phosphorylated STATs that can now enter the nucleus.