Which of the given statements is incorrect about Microarray (or microchip) analysis?

• A. it is a new technology in which all of the genes of an organism are represented by oligonucleotide sequences spread out in an 80 x 80 array on microscope slides
• B. the oligonucleotide sequences cannot be synthesized directly on the slide
• C. the oligonucleotides are collectively hybridized to a labeled cdna library prepared by reverse-transcribing mrna from cells
• D. the amount of label binding to each oligonucleotide spot reflects the amount of mrna in the cell