39. Which of the following statements is incorrect regarding CRISPR? (A) CRISPR-Cas9 system requires viral DNA sequences and an enzyme to ward off the invasion of viruses. (B) CRISPR-Cas9 system guides an enzyme to segmentalize the viral genome based on the identified viral DNA sequences. (C) CRISPR-based therapy is adapted from the immune defense system in bacteria.(D) Unlike traditional gene therapy approaches. CRISPR-based therapies modify cellular genome by inserting a whole gene.