55. The initial creation of induced pluripotent stem (iPS) cells by Dr. Shinya Yamanaka (2012 Nobel Prize) from fully differentiated cells involves which specific molecular technique? (A) Introducing four master regulatory genes into a differentiated cell using a modified adenovirus. (B) Utilizing a modified retrovirus to insert cloned copies of four specific stem cell master regulatory genes into the genome of a differentiated cell. (C) Fusing a differentiated cell with an embryonic stem cell to induce reprogramming through cytoplasmic factors. (D) Directly injecting mRNA transcripts of four key transcription factors into a differentiated cell. (E) Exposing differentiated cells to a specific cocktail of growth factors and small molecules that reverse the epigenetic landscape to a pluripotent state.