Researchers are studying a DNA region of interest in an effort to learn more about the gene and its structure. Using multiple restriction enzymes, they cut the region of interest into smaller fragments ( A D ) that are each ligated into a vector. The vector contains a downstream detectable marker. The researchers transform each vector into cells and examine the expression. Determine which DNA region may contain the promoter (Pro). If it is located across multiple regions, indicate each region. Not all regions will be marked..