Which, If Any, of the Following Descriptions Is False

Multiple Choice

Which, if any, of the following descriptions is false?

A) Zinc fingers are elements of protein secondary structure in which the polypeptide chain folds back upon itself after co-ordination of a Zn²⁺ ion with selected amino acids, often a pair of cysteines and a pair of histidines.
B) Zinc finger nucleases are natural proteins containing a sequence of zinc fingers that can bind to specific sequences in DNA.
C) After zinc finger nucleases bind to both DNA strands at a specific DNA sequence they attract cellular DNA cleavage enzymes, inducing them to make a double-stranded break at just that one position in the genome.
D) The CRISPR-Cas system also allows genome editing but in this case the target DNA sequences are recognized by guide RNA sequences rather than proteins.