Both liver cells and lens cells have the genes for making the proteins albumin and crystalline. However, only liver cells express the blood protein albumin and only lens cells express crystalline, the main protein in the lens of the eye. Both of these genes have enhancer sequences associated with them.

The claim that gene regulation results in differential gene expression and influences cellular products (albumin or crystallin) is best supported by evidence in which of the following statements?

Liver cells possess transcriptional activators that are different from those of lens cells.
Liver cells and lens cells use different RNA polymerase enzymes to transcribe DNA.
Liver cells and lens cells possess the same transcriptional activators.
Liver cells and lens cells possess different general transcription factors.