Three isoforms of a particular protein (variants A, B, and C) are expressed. In the following diagram, exons are indicating by boxes, introns by the black lines, and splice junctions by blue lines. Assume each exon is greater than 500 bp in length (figure not drawn to scale). Question 12 Midterm-1.png In the absence of available antibodies for Western blotting, how would one experimentally determine if variant C was expressed in HeLa cells? Group of answer choices Quantitative real time PCR using primers designed to amplify a region from exon 1 to 5' end of exon 2 and 5' end of Exon 6 Quantitative real time PCR using primers to amplify a region from the 3' end of exon 1 to the 5' end of exon 4 Quantitative real time PCR using primers designed to amplify a region from the 3' end of exon 4 to the 5' end of exon 7 Quantitative real time PCR using primers to amplify a region from the 3' end of exon 3 to the 5' end of exon 7