To Analyze Whether a Putative Transcriptional Enhancer Activates Transcription, One

To analyze whether a putative transcriptional enhancer activates transcription, one could use which of the following approaches?

A) attach the enhancer to a reporter gene in a recombinant construct; transiently transfect the construct into cells
B) attach a histidine tag to the enhancer sequence in a recombinant construct; purify the complex using nickel-nitrilotriacetic acid (Ni-NTA) resin
C) co-transfect the enhancer sequence with a plasmid encoding RNA polymerase; perform in vitro transcription
D) use in vitro mutagenesis to disrupt the enhancer; immunoprecipitate the enhancer