Which of the following is not true about CRISPR/Cas9 system ...

Which of the following is not true about CRISPR/Cas9 system ?A.The system contains a gRNA and an exo nuclease CRSPR refers to c lustered regularly interspaced short palindromic repeat A gRNA guides the endonuclease to load on a DNA target and cut itt is a part of immunity system of bacterium used to resist the foreign DNA The system contains a gRNA and an endonuclease