Answer: Â a, b, d, c, e, f
Explanation: The steps of Cas9 DNA recognition and cleavage goes in the following order lettered A, B, D, C, E and F. Cas9 recognizes and binds the sgRNA after which it binds to the double stranded DNA. It then unwinds and scans the dsDNA for its protospacer adjacent motif sequence (PAM) and on recognition the sgRNA binds to its complementary sequence followed by cleavage of the DNA at two points. That is how the double stranded break is created.